Aon (AON) 10-K risk factor changes: FY2025 vs FY2024

Risks Related to Technology, Cybersecurity, [removed: and Data Protection][added: Data]

Economic downturns, volatility, or uncertainty in the broader economy or in specific markets (including as a result of endemics or pandemics, climate change, political unrest, actions by [added: governments and] central banks, or otherwise) have caused in the past and may in the future cause reductions in technology and discretionary spending by our clients, which may result in reductions in the growth of new business or reductions in existing business.

Downward fluctuations in the year-over-year insurance premiums charged by insurers to protect against the same risk, referred to in the industry as softening of the insurance market, [added: has and] could adversely affect these businesses as a significant portion of [removed: the] [added: our] revenue is determined as a percentage of premiums charged to our clients.

Also, error and omission claims against us, which we refer to as E&O claims, may increase in economic downturns or due to [removed: other] natural or human-caused disasters, also adversely affecting our business.

As a global professional services firm, we compete with a broad variety of firms, including global, national, regional, and local insurance companies that market and service their own products, other financial services providers, brokers, and investment managers, independent firms, and consulting organizations affiliated with accounting, information systems, [removed: technology] [added: technology,] and human resources [removed: consulting.][added: consulting firms.]

Alliances or mergers among competitors could [added: also] affect our business.

Competitors may be able to innovate faster and respond better to evolving client demand and industry conditions, or may price their products in a [removed: manner that clients find] more attractive [removed: than Aon’s offerings.][added: manner.]

[removed: Further, new and non- traditional competitors,] [added: other advanced technologies),] our clients’ increasing ability and determination to self-insure, and capital market alternatives to traditional insurance and reinsurance markets [removed: cause additional forms of competition] [added: create an even more dynamic, competitive,] and [removed: innovation] [added: innovative market environment] that could affect our business.

If we are unsuccessful in innovating, if we cannot innovate as quickly as our competitors, if we are not able to make sufficient investment in innovation, if [removed: our] [added: new or existing] competitors develop more cost-effective [added: or efficient] technologies [added: or cause disintermediation] (including through the use of artificial intelligence or other emerging technologies), or if our ideas are not accepted in the marketplace, it could have a material adverse effect on our ability to obtain and complete client [removed: engagements.][added: engagements or on our financial condition and results of operations.]

Our competitors have [added: developed] or are developing competing data and analytics tools, and their success in this space may impact our ability to differentiate our own data and analytics tools.

Innovations in software, cloud computing, data and analytics, generative [added: and agentic] artificial intelligence, or other technologies that alter how our services are delivered could significantly undermine our investment in the business if we are slow to innovate or unable to take advantage of these developments.

Such risks include [added: without limitation] the investment of significant time and resources; the possibility that these efforts will not be successful [removed: and could] [added: or] result in reputational damage to us; the possibility that the marketplace does not accept our products or services or that we are unable to retain clients that adopt our new products or services; [added: the risk that our governance process] and [added: controls in these new areas may not be effective or consistent with legal, regulatory, or client requirements or expectations and] the risk of new or additional liabilities associated with these efforts, including potential E&O or other claims.

For example, we continue to invest in artificial intelligence, particularly in generative artificial intelligence tools, and [removed: have developed] [added: maintain] governance and oversight measures regarding its use.

Certain use cases of artificial intelligence in our business processes could pose [added: strategic,] operational, [removed: legal] [added: legal, ethical, regulatory] or reputational risks where there may be incorrect outputs or bias in those systems or processes, [added: potential infringement of intellectual property rights, exposure of proprietary] or [added: personal information, heightened cybersecurity risks and challenges in safely deploying, governing or controlling artificial intelligence systems or] where there is inadequate human oversight.

[removed: A client] [added: Clients have claimed and] may [added: in the future] claim [removed: it] [added: they have] suffered losses due to reliance on our consulting advice, analysis, or reporting, which poses risks of liability exposure and costs of defense and increased insurance premiums.

Adverse statements or claims from clients (including clients in the public sector or whose activities are frequently covered by the press) may receive media attention or [added: other publicity.]

Damage to our reputation, including as a result of negative perceptions or publicity regarding a [added: particular business partner,] class of business, environmental matters, climate change, workforce make-up, pay equity, harassment, social justice, [removed: cyber security,] [added: cybersecurity,] data privacy and data protection, use of artificial intelligence or innovative technology, or our inability to meet commitments or client and stakeholder expectations [removed: with respect to such matters, could affect the confidence of our clients, rating agencies, regulators, stockholders, employees and third parties in transactions that are important to our business adversely affecting our business, financial condition, and operating results.]

The potential for changes in premium rates is significant, due to pricing cyclicality in the [removed: commercial] insurance and reinsurance markets.

In addition to movements in premium rates, our ability to generate premium-based commission revenue [removed: may] [added: has been and could in the future] be challenged by:

- the growing number of technology-enabled competitors offering new risk-transfer solutions that eliminate the traditional broker-client relationship in both [removed: commercial] insurance and reinsurance markets.

As we adapt to changes in our business and the market, adapt to the regulatory environment, enter into new engagements, acquire additional businesses, and take on new employees in new locations, we may not be able to manage our large, [removed: diverse and] changing workforce, effectively control our costs, or improve our efficiency.

The prices we are able to charge for our services are affected by a number of [added: factors, including competitive factors, the extent of ongoing clients’ perception of our ability to add value through our services, and general economic conditions.]

Approximately [removed: 51.2%] [added: 51.8%] of our consolidated revenue is non-U.S., attributed on the basis of where the services are performed, and where products are sold, and the exposures created can have significant currency volatility.

Operating funds available for corporate use were [removed: $1.3] [added: $2.8] billion at December 31, [removed: 2024] [added: 2025] and are reported in Cash and cash equivalents and Short-term investments.

Of the total balance, [removed: $123] [added: $180] million was restricted to its use as of December 31, [removed: 2024.][added: 2025.]

Funds held on behalf of clients and insurers were [removed: $7.2] [added: $7.4] billion at December 31, [removed: 2024] [added: 2025] and are reported in Fiduciary assets.

As of December 31, [removed: 2024,] [added: 2025,] these long-term investments had a carrying value of [removed: $90] [added: $192] million.

Variations or developments in connection with any of these factors could cause [added: significant changes to our financial position and results of operations from year to year.]

As of December 31, [removed: 2024,] [added: 2025,] we had total consolidated debt outstanding of approximately [removed: $17.0] [added: $15.2] billion.

As of December 31, [removed: 2024,] [added: 2025,] we had two primary committed credit facilities [removed: outstanding, as well as a delayed draw term loan.][added: outstanding.]

The credit facilities are intended to support our commercial paper obligations and our general working capital [removed: needs, and the delayed draw term loan was drawn upon in full in April 2024 to support the acquisition of NFP.][added: needs.]

In addition, each of our committed credit facilities [removed: and the term loan] included customary representations, warranties, and covenants, including financial covenants that require us to maintain specified ratios of adjusted consolidated EBITDA to consolidated interest expense and consolidated debt to adjusted consolidated EBITDA, tested quarterly.

This in turn may [removed: have the] impact [removed: of reducing] our flexibility to respond to changing business and economic conditions, thereby placing us at a relative disadvantage compared to competitors that have less indebtedness, or fewer or less onerous covenants associated with such indebtedness, and making us more vulnerable to general adverse economic and industry conditions.

If we cannot service our [removed: indebtedness,] [added: indebtedness or continue to meet the terms of our financial covenants,] we may have to take actions such as selling assets, seeking additional equity, or reducing or delaying capital expenditures, strategic acquisitions, investments, and alliances, any of which could impede the implementation of our business strategy or prevent us from entering into transactions that would otherwise benefit our business.

Our senior debt ratings at December 31, [removed: 2024] [added: 2025] were A- with a [removed: negative] [added: stable] outlook (S&P), BBB+ with a stable outlook (Fitch), and Baa2 with a [removed: stable] [added: positive] outlook (Moody’s).

[removed: Ireland, the U.K., Singapore, and many E.U. member states, among others, have enacted] legislation to implement the global minimum tax that is generally consistent with the OECD’s Pillar Two tax regime.

[removed: There can be no assurance that we would] [added: We may] be [removed: successful in attempting] [added: unable] to mitigate the adverse impacts resulting from any changes in tax laws and regulations, including any changes in the interpretation of such tax authorities, or from audits and other matters.

As a holding company without significant operations of its own, our principal assets are the shares of capital stock of our [added: subsidiaries.]

[removed: No assurance can be given that there will not be further changes] [added: Changes] in law, regulatory actions, or other circumstances [removed: that] could restrict the ability of our subsidiaries to pay dividends or otherwise make [removed: payments to us.]

E&O claims include, for example, the failure of our employees or sub-agents, whether negligently or intentionally, to place coverage correctly or notify carriers of claims on behalf of clients, to provide insurance carriers with complete and accurate information relating to the risks being insured, or the failure to give error-free consulting, financial, [removed: or] investment [added: or other] advice.

- Regulation in the areas of data privacy, data protection, data management, data transfer, data localization, artificial intelligence, and cybersecurity could increase our costs and affect or limit our business opportunities.

Further, new and non- traditional competitors (including “InsurTech” firms utilizing artificial intelligence or

with respect to such matters, could affect the confidence of our clients, rating agencies, regulators, stockholders, employees and third parties in transactions that are important to our business adversely affecting our business, financial condition, and operating results.

Ireland, the U.K., Singapore, and many E.U. member states, among others, have enacted

There remains significant uncertainty as to how Pillar Two applies to Aon in prior years and how its application might change in the future.

payments to us.

Furthermore, our subsidiaries may be unable to make timely payments to us when needed, which could impair our ability to meet our obligations, pay dividends, repurchase shares, or fund other aspects of our operations and corporate expenses.

Increased scrutiny of corporate sustainability claims, and changes in client and investor preferences may also create legal, regulatory, contractual, and reputational risks and could require changes to our products, services, client engagements or operations, which may increase our cost of doing business.

Additionally, competition for professional

personnel remains intense, and competitors are using increasingly aggressive measures to recruit professional talent in our industry.

- difficulties in transitioning operations from one country to another without interruption or reduction in the quality of those operations;

- attracting, identifying and retaining qualified personnel in the countries in which we operate;

strategic asset.

An interruption in or

we engage, insiders or employees.

Regulation in the areas of data privacy, data protection, data management, data transfer, data localization, artificial intelligence, and cybersecurity could increase our costs and affect or limit our business opportunities.

require significant effort to review changes to IT systems and transfer methods.

favor of the holders of shares where the shares (or rights to acquire shares) attributable to such holders are proportional to the respective number of shares held by them; and (ii) otherwise, for up to approximately twenty percent of the Company’s issued share capital as of April 11, 2025.

Risks Related to the Acquisition of NFP

- We may not be able to integrate the NFP business successfully or manage the combined business effectively, and many of the anticipated synergies and other benefits may not be realized or may not be realized within the expected time frame.

- We have incurred and may continue to incur significant integration-related costs in connection with the acquisition of NFP.

other publicity.

factors, including competitive factors, the extent of ongoing clients’ perception of our ability to add value through our services, and general economic conditions.

significant changes to our financial position and results of operations from year to year.

In the U.S., the Inflation Reduction Act introduced, among other changes, a 1% excise tax on certain stock redemptions by U.S. corporations (which the U.S. Treasury indicated may also apply to certain stock redemptions of foreign corporations deemed funded by their U.S. affiliates).

There remains significant uncertainty as to how Pillar Two will ultimately apply to Aon.

subsidiaries.

Furthermore, no assurance can be given that our subsidiaries may be able to make timely payments to us in order for us to meet our obligations.

filing of additional lawsuits.

In addition, we may not be able to adequately address such conflicts of interest.

known as MDI.

While accepting MDI is a lawful and acceptable business practice, we cannot predict whether our position will result in regulatory or other scrutiny and our controls may not be fully effective.

If we cannot

operations, impact our ability to offer certain products and services, and result in contractual or regulatory penalties, liability claims from clients, or employees, damage to our reputation, and harm to our business.

which have been successful and have resulted in unauthorized access to our systems and data.

Further, regulatory initiatives in the area of data privacy and data

We may not be able to integrate the NFP business successfully or manage the combined business effectively, and many of the anticipated synergies and other benefits of acquiring NFP may not be realized or may not be realized within the expected time frame.

We have devoted management attention and resources to integrating our and NFP's business practices so that we can fully realize the anticipated benefits of the NFP acquisition.

Nonetheless, the business and assets acquired may not be successful or may require greater resources and investments than originally anticipated.

Further, it is possible that the integration process could take longer than anticipated or that the management of the combined organizations and achievement of anticipated synergies could be more difficult than expected.

The integration process is subject to a number of risks and uncertainties, and no assurance can be given that the anticipated benefits of the acquisition will be realized or, if realized, the timing of their realization.

Failure to achieve these anticipated benefits could adversely affect Aon’s future businesses, financial condition, results of operations and prospects.

We have incurred and may continue to incur significant integration-related costs in connection with the acquisition of NFP.

Aon has incurred and expects to continue to incur a number of non-recurring costs associated with the NFP acquisition and combining the operations of the two companies, which could adversely affect Aon’s ability to execute its integration plan and achieve the anticipated benefits of the NFP acquisition.

Although Aon expects that the elimination of duplicative costs, as well as the realization of other efficiencies related to the integration of the businesses of Aon and NFP, should allow Aon to offset integration-related costs over time, this net benefit may not be achieved in the near term or at all.

EXECUTIVE SUMMARY OF [removed: 2024] [added: 2025] FINANCIAL RESULTS

The following is a summary of our [removed: 2024] [added: 2025] financial results:

- Revenue increased [removed: $2.3] [added: $1.5] billion, or [removed: 17%,] [added: 9%,] to [removed: $15.7] [added: $17.2] billion, reflecting [removed: acquired revenues from NFP and] 6% organic revenue growth, driven by net new business and ongoing strong [removed: retention.][added: retention and acquired revenues from NFP.]

[removed: - Operating expenses increased $2.3 billion, or 24%, to $11.9 billion in 2024 due] [added: The increase was] primarily [added: due] to the inclusion of [removed: NFP’s] [added: ongoing] operating [removed: expenses,] [added: expenses from NFP and] an increase in [removed: expense] [added: expenses] associated with 6% organic revenue growth, [removed: Accelerating Aon United restructuring charges, and transaction and integration costs,] partially offset by [removed: $110 million of] [added: savings from Accelerating Aon United] restructuring [removed: savings.][added: actions.]

Risk Capital operating expenses increased [removed: $647] [added: $629] million, or [removed: 10%,] [added: 9%,] to [removed: $7.2] [added: $7.9] billion and Human Capital operating expenses increased [removed: $1.3 billion,] [added: $431 million,] or [removed: 47%,] [added: 11%,] to [removed: $4.1] [added: $4.5] billion in [removed: 2024] [added: 2025] compared to [removed: 2023.][added: 2024.]

- Operating margin [removed: decreased] [added: increased] to [removed: 24.4%] [added: 25.3%] in [removed: 2024] [added: 2025] from [removed: 28.3%] [added: 24.4%] in [removed: 2023,] [added: 2024,] driven primarily by [removed: the addition] [added: organic revenue growth] of [removed: NFP] [added: 6%] and [added: $160 million of net restructuring savings, partially offset by] an increase in operating expenses as previously described, [removed: partially offset by organic revenue growth] [added: the addition] of [removed: 6%] [added: NFP] and [removed: $110 million of net restructuring savings.][added: lower fiduciary investment income.]

Risk Capital operating margin [removed: increased] [added: decreased] to [removed: 31.3%] [added: 30.4%] in [removed: 2024] [added: 2025] from [removed: 30.9%] [added: 31.3%] in [removed: 2023] [added: 2024] and Human Capital operating margin [removed: decreased] [added: increased] to [removed: 21.9%] [added: 23.9%] in [removed: 2024] [added: 2025] from [removed: 28.4%] [added: 21.9%] in [removed: 2023.][added: 2024.]

- Due to the factors set forth above, [removed: Net] [added: as well as the $1.2 billion gain from the disposal of the NFP Wealth business, net] income was [removed: $2.7] [added: $3.8] billion in [removed: 2024,] [added: 2025,] an increase of [removed: $92 million,] [added: $1.0 billion,] or [removed: 4%,] [added: 38%,] from [removed: 2023.][added: 2024.]

- Diluted earnings per share was [removed: $12.49] [added: $17.02] per share in [removed: 2024] [added: 2025] compared to [removed: $12.51] [added: $12.49] per share in the prior year period.

- Cash flows provided by operating activities was [removed: $3.0] [added: $3.5] billion in [removed: 2024, a decrease] [added: 2025, an increase] of [removed: $400] [added: $446] million, or [removed: 12%,] [added: 15%,] from [removed: $3.4] [added: $3.0] billion in [removed: 2023, primarily] [added: 2024,] due [removed: to higher cash taxes, payments related] [added: primarily] to [removed: restructuring, legal settlement expenses, and transaction and integration costs, partially offset by] strong adjusted operating income growth and [added: lower NFP-related transaction costs, partially offset by] working capital [removed: improvements.][added: headwinds.]

We focus on four key [removed: metrics,] [added: metrics] that are not presented in accordance with U.S. [removed: GAAP that] [added: GAAP, which] we communicate to shareholders: organic revenue growth, adjusted operating margin, adjusted diluted earnings per share, and free cash flow.

The following is our measure of performance against these four metrics for [removed: 2024:][added: 2025:]

- Organic revenue growth, a non-GAAP measure defined under the caption “Review of Consolidated Results — Organic Revenue Growth,” was 6% in [added: both 2025 and] 2024, [removed: compared to 7% organic growth in the prior year period,] driven by net new business and ongoing strong [removed: retention.][added: retention, as well as positive net market impact.]

- Adjusted operating margin, a non-GAAP measure defined under the caption “Review of Consolidated Results — Adjusted Operating Margin,” was [removed: 31.5%] [added: 32.4%] in [removed: 2024,] [added: 2025,] compared to [removed: 31.6%] [added: 31.5%] in the prior year.

The [removed: decrease] [added: increase] in adjusted operating margin primarily reflects [removed: the addition of NFP and increased expenses, partially offset by 6%] organic revenue growth [removed: and $110] [added: of 6%, $160] million of [added: additional] net restructuring [removed: savings.][added: savings and a decrease in incentive compensation, partially offset by the addition of NFP, an increase in operating expenses as previously described and lower fiduciary investment income.]

Risk Capital adjusted operating margin [removed: increased] [added: decreased] to [removed: 34.6%] [added: 34.3%] in [removed: 2024] [added: 2025] from [removed: 34.2%] [added: 34.6%] in [removed: 2023] [added: 2024] and Human Capital adjusted operating margin [removed: decreased] [added: increased] to [removed: 29.5%] [added: 32.2%] in [removed: 2024] [added: 2025] from [removed: 29.9%] [added: 29.5%] in [removed: 2023.][added: 2024.]

- Adjusted diluted earnings per share, a non-GAAP measure defined under the caption “Review of Consolidated Results — Adjusted Diluted Earnings per Share,” was [removed: $15.60] [added: $17.07] per share in [removed: 2024,] [added: 2025,] an increase of [removed: $1.46] [added: $1.47] per share, or [removed: 10%,] [added: 9%,] from [removed: $14.14] [added: $15.60] per share in [removed: 2023.][added: 2024.]

- Free cash flow, a non-GAAP measure defined under the caption “Review of Consolidated Results — Free Cash Flow,” was [removed: $2.8] [added: $3.2] billion in [removed: 2024, a decrease] [added: 2025, an increase] of [removed: $366] [added: $401] million, or [removed: 11%,] [added: 14%,] from [removed: $3.2] [added: $2.8] billion in [removed: 2023,] [added: 2024,] reflecting [removed: a decrease] [added: an increase] in [removed: Cash] [added: cash] flows from operations, partially offset by a [removed: $34] [added: $45] million [removed: decrease] [added: increase] in capital expenditures.

| | | | | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | |

| Total revenue | | | | | | $ | [removed: 15,698] [added: 17,181] | | | | | $ | [removed: 13,376] [added: 15,698] | | | | | $ | [removed: 12,479] [added: 13,376] | |

| Compensation and benefits | | | | | | [removed: 8,283] [added: 8,985] | | | | | | [removed: 6,902] [added: 8,283] | | | | | | [removed: 6,477] [added: 6,902] | | |

| Information technology | | | | | | [removed: 539] [added: 568] | | | | | | [removed: 534] [added: 539] | | | | | | [removed: 509] [added: 534] | | |

| Premises | | | | | | [removed: 325] [added: 337] | | | | | | [removed: 294] [added: 325] | | | | | | [removed: 289] [added: 294] | | |

| Depreciation of fixed assets | | | | | | [removed: 183] [added: 188] | | | | | | [removed: 167] [added: 183] | | | | | | [removed: 151] [added: 167] | | |

| Amortization and impairment of intangible assets | | | | | | [removed: 503] [added: 778] | | | | | | [removed: 89] [added: 503] | | | | | | [removed: 113] [added: 89] | | |

| Other general expense | | | | | | [removed: 1,641] [added: 1,616] | | | | | | [removed: 1,470] [added: 1,641] | | | | | | [removed: 1,271] [added: 1,470] | | |

| Accelerating Aon United Program expenses | | | | | | [removed: 389] [added: 365] | | | | | | [removed: 135] [added: 389] | | | | | | [removed: —] [added: 135] | | |

| Total operating expenses | | | | | | [removed: 11,863] [added: 12,837] | | | | | | [removed: 9,591] [added: 11,863] | | | | | | [removed: 8,810] [added: 9,591] | | |

| Operating income | | | | | | [removed: 3,835] [added: 4,344] | | | | | | [removed: 3,785] [added: 3,835] | | | | | | [removed: 3,669] [added: 3,785] | | |

| Interest income | | | | | | [removed: 67] [added: 19] | | | | | | [removed: 31] [added: 67] | | | | | | [removed: 18] [added: 31] | | |

| Interest expense | | | | | | [removed: (788)] [added: (815)] | | | | | | [removed: (484)] [added: (788)] | | | | | | [removed: (406)] [added: (484)] | | |

| Other income (expense) | | | | | | [removed: 348] [added: 1,211] | | | | | | [removed: (163)] [added: 348] | | | | | | [removed: (125)] [added: (163)] | | |

| Income before income taxes | | | | | | [removed: 3,462] [added: 4,759] | | | | | | [removed: 3,169] [added: 3,462] | | | | | | [removed: 3,156] [added: 3,169] | | |

| Income tax expense | | | | | | [removed: 742] [added: 1,009] | | | | | | [removed: 541] [added: 742] | | | | | | [removed: 510] [added: 541] | | |

| Net income | | | | | | [removed: 2,720] [added: 3,750] | | | | | | [removed: 2,628] [added: 2,720] | | | | | | [removed: 2,646] [added: 2,628] | | |

| Less: Net income attributable to redeemable and nonredeemable noncontrolling interests | | | | | | [removed: 66] [added: 55] | | | | | | [removed: 64] [added: 66] | | | | | | [removed: 57] [added: 64] | | |

| Net income attributable to Aon shareholders | | | | | | $ | [removed: 2,654] [added: 3,695] | | | | | $ | [removed: 2,564] [added: 2,654] | | | | | $ | [removed: 2,589] [added: 2,564] | |

| Diluted net income per share attributable to Aon shareholders | | | | | | $ | [removed: 12.49] [added: 17.02] | | | | | $ | [removed: 12.51] [added: 12.49] | | | | | $ | [removed: 12.14] [added: 12.51] | |

| Weighted average ordinary shares outstanding - diluted | | | | | | [removed: 212.5] [added: 217.1] | | | | | | [removed: 205.0] [added: 212.5] | | | | | | [removed: 213.2] [added: 205.0] | | |

| Total revenue | | | $ | [removed: 10,517] [added: 11,290] | | | | | $ | [removed: 9,524] [added: 10,517] | | | | | $ | [removed: 5,209] [added: 5,907] | | | | | $ | [removed: 3,864] [added: 5,209] | | | | | $ | [removed: (28)] [added: (16)] | | | | | $ | [removed: (12)] [added: (28)] | | | | | $ | [removed: 15,698] [added: 17,181] | | | | | $ | [removed: 13,376] [added: 15,698] | |

Risk Capital revenue increased $773 million, or 7%, to $11.3 billion and Human Capital revenue increased $698 million, or 13%, to $5.9 billion in 2025 compared to 2024.

- Operating expenses increased $1.0 billion, or 8%, to $12.8 billion in 2025 due primarily to the inclusion of NFP’s operating expenses and an increase in expenses associated with 6% organic revenue growth, partially offset by $160 million of additional net restructuring savings and lower NFP transaction- and integration-related expense.

| | | | 2025 | | | | | | 2024 | | | | | | 2025 | | | | | | 2024 | | | | | | 2025 | | | | | | 2024 | | | | | | 2025 | | | | | | 2024 | | |

Performance was highlighted by strong growth in U.S. core P&C and double-digit increases in M&A services and construction.

Results were partially offset by slightly unfavorable market impact in the year.

Organic revenue growth was 5% in 2025 reflecting growth in both Investments and Retirement.

Growth in Investments was driven by net asset inflows and market performance and includes the impact of strong organic revenue growth from the divested NFP Wealth business, as defined in Liquidity and Financial Condition, until classified as held for sale in September 2025.

Compensation and benefits increased $702 million, or 8%, in 2025 compared to 2024.

Depreciation of fixed assets increased $5 million, or 3%, in 2025 compared to 2024, due primarily to an increase in fixed assets acquired from NFP.

Other general expenses decreased $25 million, or 2%, in 2025 compared to 2024.

If interest expense on these assets exceeds interest income for the period, the net amount is reported as interest expense for both the quarterly and year-to-date periods.

The 2025 tax rate was driven by the geographical distribution of income, including an unfavorable impact from the gain on sale of a business.

In addition, the tax rate was impacted by certain discrete items, including the tax benefit associated with the sale of certain assets and liabilities and share-based payments partially offset by the unfavorable impact of other discrete items.

There remains significant uncertainty, however, as to how Pillar Two applies to the Company in prior years and how its application may change in future years.

| Reinsurance Solutions | | | | | | 2,793 | | | | | | 2,656 | | | | | | 5 | | | | | | — | | | | | | (1) | | | | | | — | | | | | | 6 | | |

| Health Solutions | | | | | | 3,839 | | | | | | 3,335 | | | | | | 15 | | | | | | — | | | | | | — | | | | | | 10 | | | | | | 5 | | |

| Wealth Solutions | | | | | | 2,068 | | | | | | 1,874 | | | | | | 10 | | | | | | 1 | | | | | | — | | | | | | 4 | | | | | | 5 | | |

| Total revenue | | | | | | $ | 17,181 | | | | | $ | 15,698 | | | | | 9% | | | | | | 1% | | | | | | —% | | | | | | 2% | | | | | | 6% | | |

| Operating income | | | $ | 3,436 | | | | | $ | 3,292 | | | | | $ | 1,410 | | | | | $ | 1,143 | | | | | $ | (502) | | | | | $ | (600) | | | | | $ | 4,344 | | | | | $ | 3,835 | |

| Operating margin | | | 30.4 | | % | | | | 31.3 | | % | | | | 23.9 | | % | | | | 21.9 | | % | | | | | | | | | | | | | | | | 25.3 | | % | | | | 24.4 | | % |

No transaction costs were recognized for the twelve months ended December 31, 2025.

Aon incurred $77 million and $95 million of integration costs in the twelve months ended December 31, 2025 and 2024, respectively.

| Operating income | | | | | | $ | 4,344 | | | | | $ | 1,219 | | | | | $ | 5,563 | |

| Income before income taxes | | | | | | 4,759 | | | | | | (88) | | | | | | 4,671 | | |

| Income tax expense (4) | | | | | | 1,009 | | | | | | (99) | | | | | | 910 | | |

| Net income | | | | | | 3,750 | | | | | | 11 | | | | | | 3,761 | | |

(1)For the twelve months ended December 31, 2025 and 2024, Other income was $1,211 million and $348 million, respectively.

Adjusted other expense for the twelve months ended December 31, 2025 was $96 million compared to Adjusted other income of $13 million for the twelve months ended December 31, 2024.

During the twelve months ended December 31, 2025 and 2024, the Company recognized gains of $108 million and $84 million, respectively.

(3)Adjusted other income (expense) for the twelve months ended December 31, 2025 excluded gains from the disposal of NFP Wealth business totaling $1,199 million.

| | | | | | | 2025 | | | | | | 2024 | | |

Entities with a negative cash pool position incur interest expense, while those with a positive position earn interest income.

Interest rates are determined by local market conditions and vary by currency.

For the period, if interest expense on negative cash pool balances exceeds interest income associated with positive cash pool balances, as well as other income-producing assets, the net amount is reported as interest expense for both the quarterly and year-to-date periods.

| Money market funds | | | — | | | | | | 1,603 | | | | | | 3,395 | | | | | | 4,998 | | |

| Total | | | $ | 1,195 | | | | | $ | 1,603 | | | | | $ | 17,889 | | | | | $ | 20,687 | |

| | | | | | | 2025 | | | | | | 2024 | | |

| Cash provided by operating activities | | | | | | $ | 3,481 | | | | | $ | 3,035 | |

| Charges | | | 195 | | | | | | 155 | | | | | | 15 | | | | | | 365 | | |

| Cash payments | | | (165) | | | | | | (132) | | | | | | — | | | | | | (297) | | |

Risk Capital revenue increased $1.0 billion, or 10%, to $10.5 billion and Human Capital revenue increased $1.3 billion, or 35%, to $5.2 billion in 2024 compared to 2023.

ENVIRONMENTAL, SOCIAL, AND GOVERNANCE

For many companies, the management of ESG risks and opportunities has become increasingly important, and ESG-related challenges, such as extreme weather events, supply chain disruptions, cyber events, regulatory changes, ongoing public health impacts, and the increased focus on workforce resilience in various work environments, continue to create volatility and uncertainty for our clients.

At Aon, helping clients manage risk - including ESG risk - is at the core of what we do.

We offer a wide range of risk assessment, consulting, and advisory solutions, many of which are significant parts of our core business offerings, designed to address and manage ESG issues for clients, and to enable our clients to create more sustainable value.

We see significant opportunity in enhancing our impact and delivering innovative client solutions on ESG matters.

ACQUISITION OF NFP

On April 25, 2024, the Company completed its acquisition of NFP, a leading middle-market provider of property and casualty brokerage, benefits consulting, wealth management, and retirement plan consulting, with more than 7,700 colleagues.

The Company acquired NFP Intermediate Holdings A Corp in a cash-and-stock merger for an aggregate U.S. GAAP preliminary purchase price totaling $9.1 billion, including approximately $3.2 billion to settle NFP indebtedness and cash consideration to the selling shareholders, and approximately 19 million class A ordinary shares with a fair value of approximately $5.9 billion, based on the Company’s closing stock price on April 25, 2024.

In addition, the company had other adjustments of $3.9 billion for cash and certain assumed liabilities.

Our segment results are as follows (in millions):

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| | | | Twelve Months Ended December 31, | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| | | | Risk Capital | | | | | | | | | | | | Human Capital | | | | | | | | | | | | Corporate/Eliminations (1) | | | | | | | | | | | | Total Consolidated | | | | | | | | |

| | | | 2024 | | | | | | 2023 | | | | | | 2024 | | | | | | 2023 | | | | | | 2024 | | | | | | 2023 | | | | | | 2024 | | | | | | 2023 | | |

| Revenue | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| Expenses | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

(1)Segment expenses exclude governance costs, post-retirement benefits, and other costs that are not directly attributable to a specific segment.

(2)Includes expenses related to Depreciation of fixed assets, Amortization and impairment of intangible assets, Accelerating Aon United Program expenses, and Other general expenses.

Revenue

Performance was highlighted by strength in North America core P&C, strong growth internationally and an increase in construction business.

Results also reflect a double-digit increase in M&A services.

In addition, market impact was modestly positive on results in the year.

Growth in Investments was highlighted by strong revenue growth within NFP, driven by net asset inflows and market performance.

Compensation and benefits increased $1.4 billion, or 20%, in 2024 compared to 2023.

The increase was primarily due to the inclusion of ongoing operating expenses from NFP, partially offset by efficiencies from our Aon Business Services operating platform and savings from Accelerating Aon United restructuring actions.

Depreciation of fixed assets increased $16 million, or 10%, in 2024 compared to 2023, due primarily to the inclusion of operating expenses from NFP, partially offset by savings from Accelerating Aon United restructuring actions.

Other general expenses increased $171 million, or 12%, in 2024 compared to 2023.

Total Operating Expenses and Operating Income

The 2023 tax rate was primarily driven by the geographical distribution of income and certain discrete items, including the tax benefits associated with the release of a valuation allowance, and share-based payments.

There remains significant uncertainty, however, as to how Pillar Two will ultimately apply to the Company.

Due to our change in reportable segments in the fourth quarter of 2024, a discussion of our segment results for 2023 compared to 2022 is included below.

| | | | 2023 | | | | | | 2022 | | | | | | 2023 | | | | | | 2022 | | | | | | 2023 | | | | | | 2022 | | | | | | 2023 | | | | | | 2022 | | |

| Total revenue | | | $ | 9,524 | | | | | $ | 8,905 | | | | | $ | 3,864 | | | | | $ | 3,591 | | | | | $ | (12) | | | | | $ | (17) | | | | | $ | 13,376 | | | | | $ | 12,479 | |

| Compensation and benefits | | | 4,800 | | | | | | 4,532 | | | | | | 2,003 | | | | | | 1,856 | | | | | | 99 | | | | | | 89 | | | | | | 6,902 | | | | | | 6,477 | | |

| Information technology | | | 385 | | | | | | 361 | | | | | | 148 | | | | | | 146 | | | | | | 1 | | | | | | 2 | | | | | | 534 | | | | | | 509 | | |

| Premises | | | 204 | | | | | | 195 | | | | | | 88 | | | | | | 88 | | | | | | 2 | | | | | | 6 | | | | | | 294 | | | | | | 289 | | |

| Other expenses (2) | | | 1,189 | | | | | | 922 | | | | | | 528 | | | | | | 540 | | | | | | 144 | | | | | | 73 | | | | | | 1,861 | | | | | | 1,535 | | |

| Total operating expenses | | | 6,578 | | | | | | 6,010 | | | | | | 2,767 | | | | | | 2,630 | | | | | | 246 | | | | | | 170 | | | | | | 9,591 | | | | | | 8,810 | | |

[removed: At December 31, 2024, we have hedged approximately] [added: We generally hedge up to] 45% of our U.K. subsidiaries’ expected exposures to transactions denominated in U.S. dollar, euro, and Japanese [removed: yen for the years ending December 31, 2025 and 2026, respectively.][added: yen.]

If we were to hypothetically translate prior year results at current year exchange rates, diluted earnings per share would have an unfavorable [removed: $0.11] [added: $0.03] comparable impact during the year ended December 31, [removed: 2024.][added: 2025.]

Further, adjusted diluted earnings per share, a non-GAAP measure as defined and reconciled under the caption “Review of Consolidated Results — Adjusted Diluted Earnings Per Share,” would have an unfavorable [removed: $0.12] [added: $0.01] comparable impact during the year ended December 31, [removed: 2024] [added: 2025] if we were to hypothetically translate prior year results at current year exchange rates.

A hypothetical, instantaneous parallel decrease in the year-end yield curve of 100 BPS would cause a decrease, net of derivative positions, of [removed: $71] [added: $77] million to each of [removed: 2025 and] 2026 [added: and 2027] pretax income.

A corresponding increase in the year-end yield curve of 100 BPS would cause an increase, net of derivative positions, of [removed: $71] [added: $77] million to each of [removed: 2025 and] 2026 [added: and 2027] pre-tax income.

We have long-term debt outstanding, excluding the current portion, with a fair market value of [removed: $15.3] [added: $14.2] billion and [removed: $9.2] [added: $15.3] billion as of December 31, [removed: 2024] [added: 2025] and December 31, [removed: 2023,] [added: 2024,] respectively.

The fair value was less than the carrying value by [removed: $957] [added: $502] million at December 31, [removed: 2024,] [added: 2025,] and [removed: $772] [added: $957] million less than the carrying value at December 31, [removed: 2023.][added: 2024.]

A hypothetical 1% increase or decrease in interest rates would change the fair value by a decrease of 7% or an increase of 8%, respectively, at December 31, [removed: 2024.][added: 2025.]

Aon plc (which may be referred to as “Aon,” the “Company,” “we,” “us,” or “our”) is a leading global professional services [removed: firm providing a broad range of Risk Capital and Human Capital solutions.][added: firm.]

[removed: Our] [added: We serve] clients [removed: are] in [removed: over] [added: more than] 120 countries [removed: and include] [added: across] all market segments and [removed: almost] [added: nearly] every industry.

This diversification of our [removed: customer] [added: client] base helps provide [removed: us] [added: our firm with] stability in different economic scenarios that could affect specific industries, customer segments, or geographies.

We [removed: have continued] [added: continue] to focus our portfolio on higher-margin, capital-light professional services businesses that have high recurring revenue streams and strong cash flow generation.

In [removed: 2024,] [added: 2025,] our consolidated Total revenue was [removed: $15,698] [added: $17,181] million.

This includes [removed: $10,517] [added: $11,290] million in Risk Capital and [removed: $5,209] [added: $5,907] million in Human Capital before certain intercompany eliminations.

Commercial Risk’s global reach enables seamless client service in all geographies including Aon’s Global Broking Centers in London, [removed: Bermuda] [added: Bermuda,] and Singapore.

[added: Strategy and Technology Group combines strategic advice with] data-driven consulting, analytics, and modeling tools, including [removed: Tyche,] [added: Capital Insights Explorer,] ReMetrica, and PathWise, to help clients deploy capital efficiently and effectively.

We partner with insurers, reinsurers, investment firms, and corporations in executing innovative risk management products, capital market [removed: solutions] [added: solutions,] and corporate finance advisory services.

*Health Solutions* includes consulting and brokerage, consumer benefits, [added: compensation,] and talent advisory services.

We support clients across the full employee lifecycle, including talent assessment and selection, compensation benchmarking, total rewards strategy optimization, Corporate [removed: Governance, ESG consulting,] [added: Governance] and strategic employee communications.

Our investments advisory team provides corporations, public pensions, endowments and foundations with advice on developing and maintaining investment programs across a broad range of plan types, including defined benefit [removed: plans, defined contribution] plans and [removed: Master Trusts.][added: defined contribution plans.]

We compete with numerous other global insurance brokers and consulting companies, including, among others, Marsh [removed: & McLennan Companies, Inc.,] [added: McLennan,] Willis Towers [removed: Watson Public Limited Company,] [added: Watson,] Arthur J Gallagher & Company, and Lockton Companies, Inc., as well as numerous other global, regional, and local firms in almost every area of our business.

See the “Risk Factors” section in Part I, Item 1A of this report for information regarding how actions by [added: governmental and] regulatory authorities or changes in legislation and regulation in the jurisdictions in which we operate may have an adverse effect on our business.

Our single largest client by revenue accounted for approximately 1% of our Total revenue in [removed: 2024.][added: 2025.]

Additionally, we place insurance with many insurance carriers, none of which individually accounted for more than 10% of the total premiums we placed on behalf of our clients in [removed: 2024.][added: 2025.]

Our culture is driven by our values – committed as one firm to our purpose, united through trust and integrity as one [removed: inclusive] team, and passionate about making our colleagues and clients successful.

Each year, Aon makes significant philanthropic contributions to [removed: various organizations,] [added: thousands of organizations and] supports numerous colleague volunteer [removed: opportunities, and][added: opportunities.]

[removed: *Colleagues*][added: *Our Colleagues*]

As of December 31, [removed: 2024,] [added: 2025,] we employed approximately 60,000 employees and conducted our operations in more than 120 countries.

Our colleagues’ [removed: diverse talents,] [added: breadth of talent,] expertise, and insights contribute to the success of both our firm and our clients, and we seek to attract, [removed: grow,] [added: develop,] and retain the best talent in the industry.

[removed: Inclusive People Leadership at Aon is designed] [added: By giving transparency into the expectations of behavior as well as accountability for contributing] to [added: our Speak Up culture, we] ensure that all colleagues – at every stage of their career journey – are equipped and motivated to deliver on our purpose and able to achieve their full [removed: potential.][added: potential in an ethical manner.]

We invest [removed: significant resources to develop] [added: deeply in developing] the talent needed to [removed: remain at the forefront] [added: stay ahead] of [added: industry] innovation and [added: to] remain [removed: an attractive] [added: a destination] employer.

[removed: These] [added: Our commitment to transparent, ongoing communication is reflected in the dynamic] channels [removed: include] [added: we offer, such as] open forums and town halls with [removed: executives,] [added: executive leaders, regular] colleague surveys, and [added: meaningful] engagement through our Business Resource Groups.

[removed: Our engagement survey process consists of frequent pulse surveys,] as well as our annual all colleague support survey which enables us to understand how colleagues are engaging with their teams, the firm, and clients.

The pulse surveys for [removed: 2024] [added: 2025] were focused on topics such as manager and leadership support, delivering on our Aon Story, colleague wellbeing, [removed: inclusion, talent acquisition and performance] [added: internal mobility] and [removed: rewards.][added: performance.]

Feedback from our workforce provides management with a better understanding of evolving colleague [removed: viewpoints,] [added: viewpoints] and ensures we are taking appropriate steps to drive colleague engagement and retention.

[removed: Twenty percent] [added: 20%] of executive discretionary incentive compensation is based on quantifiable performance against strategic people priorities, including talent retention, [removed: engagement, wellbeing] [added: engagement] and [removed: inclusion.][added: wellbeing.]

We believe that [removed: inclusive teams] [added: colleagues who feel valued] produce better insight, better [removed: solutions] [added: solutions,] and, ultimately, the best outcomes for clients and our long-term success.

Our commitment to [removed: inclusion] [added: building a culture where each colleague can thrive] starts from the top with our [removed: the] Board, including its [removed: Inclusion] [added: People] & Wellbeing Sub-Committee.

Our colleague-led Business Resource Groups also support execution and provide additional opportunities for colleagues to [removed: enhance our inclusive environment.][added: connect and deepen relationships.]

As of December 31, [removed: 2024,] [added: 2025,] our global workforce was [removed: 54%] [added: 56%] women and [removed: 46%] [added: 44%] men, and the Aon Executive Committee, which leads the firm was 53% women and 47% men.

Our U.S. workforce was [removed: 25%] [added: 23%] racially or ethnically diverse, calculated as a percentage of colleagues that have voluntarily disclosed their race or ethnicity to Aon.

Across these networks, we have [removed: 249] [added: over 200] organizations committed as of December 31, [removed: 2024.][added: 2025, committed to 10,000 total apprenticeships by 2030.]

[removed: 802] [added: 900] Aon apprentices have been hired since the inception of the program across the U.S. and U.K. Both programs are certified apprenticeship programs, by the Department of Labor in the U.S. and the Department of Education in the U.K.

Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and [removed: all] [added: any] amendments to those reports are made available free of charge through our website (https://www.aon.com) as soon as reasonably practicable after such material is electronically filed with or furnished to the SEC.

Also posted on our website are the charters for our Audit, Organization and Compensation, Governance/Nominating, and Finance Committees, and [removed: Inclusion] [added: People] & Wellbeing Sub-Committee, our [added: Corporate] Governance Guidelines, and our Code of Business Conduct.

Through actionable analytic insight, globally integrated Risk Capital and Human Capital expertise and locally relevant solutions, our colleagues provide clients with the clarity and confidence to make better risk and people decisions that protect and grow their businesses.

With clients around the world facing growing uncertainty and volatility, we remain focused on accelerating our Aon United strategy to serve clients as one globally connected firm and driving innovation to address unmet and evolving client need.

We manage our business within two reportable segments: Risk Capital and Human Capital.

Additionally, in 2025 Aon launched its proprietary Data Center Lifecycle Insurance Program designed to support data center projects from construction through ongoing operations by bringing together traditionally fragmented risk classes into a single coordinated insurance solution.

We also consult on corporate sustainability matters, supporting a wide range of risk assessment and advisory solutions designed to address and manage corporate sustainability issues and enable our clients to create long-term value.

With respect to defined contributions, we offer Master Trusts and Pooled Employer Plans.

As a leading global firm – which is going further, faster to accelerate our Aon United strategy through our 3x3 Plan, which we announced in 2023 – we are focused on attracting, developing and retaining the best talent from all backgrounds, to support our clients and grow our firm.

Our colleagues are the driving force of our Aon United Strategy.

This is why we are committed to promoting a culture and sense of belonging where colleagues can bring their authentic selves to work, where opportunity and success are driven by their capability and behavior, and where our operations reflect the clients, colleagues and communities we serve around the world.

At the manager level, 30% of senior leaders and 46% of managers are female and 70% of senior leaders and 54% of managers were male.

Our colleagues have access to a wide range of learning opportunities spanning self-guided courses, immersive virtual programs, and advanced leadership development to support every stage of their career growth.

These offerings are intentionally aligned with the Aon United strategy, ensuring colleagues gain the skills and capabilities required to lead with excellence.

Through purposeful use of technology and a blend of virtual and in-person learning, we deliver tailored, high-impact development experiences that empower colleagues to thrive and drive meaningful results for our clients.

Creating an engaging and rewarding experience for our colleagues is more than a priority; it’s fundamental to our success as a firm.

We actively seek out and value our colleagues’ perspectives, knowing their feedback is essential for driving growth and creating a workplace where everyone thrives.

These independent and voluntary groups play a powerful role in shaping our culture by providing insight, championing initiatives, and identifying opportunities to deepen our dedication to wellbeing, and belonging.

Through these collaborative efforts, we not only listen; we act, ensuring every colleague feels heard, valued, and empowered to contribute to our shared purpose.

Our listening strategy consists of frequent surveys across all stages of a colleague’s career.

Through our experience, global reach, and comprehensive analytics, we help clients meet rapidly changing, increasingly complex, and interconnected challenges related to risk and people.

We are committed to accelerating innovation to address unmet and evolving client needs so that our clients are better informed, better advised, and able to make better decisions to protect and grow their business.

Management remains focused on strengthening Aon and uniting the firm through its Aon United strategy, with capabilities delivered through Risk Capital and Human Capital and enabled by data and analytics to deliver additional insight, connectivity, and efficiency.

The Company formerly operated as one reportable segment under Aon United, which included all of Aon’s operations.

Beginning in the fourth quarter of 2024, the CODM assesses the performance of the Company and allocates resources based on two segments: Risk Capital and Human Capital.

This segmentation will align with how the Company addresses client needs, accelerating its Aon United strategy and maximizing value for Aon and its shareholders.

Differences between the reportable segments’ results and Aon’s consolidated results include certain inter-segment revenues, as well as unallocated expenses.

Prior period comparative segment information has been recast to conform with current year presentation, which reflects the way our CODM internally receives information and manages and monitors our reportable operating segment performance.

The accounting policies of the reportable segments are the same as those described in Note 2 “Summary of Significant Accounting Principles and Practices.”

Strategy and Technology Group combines strategic advice with

We also help organizations manage their balance sheet volatility.

offers paid time off to volunteer.

In 2023, we announced our 3x3 Plan to accelerate Aon United by delivering industry defining client content, unmatched capabilities, and exceptional service over three years.

Our Inclusive People Leadership strategy is a central part of our Aon United strategy and is a key enabler to realizing our aspirations and purpose as a firm.

Colleagues are invited to complete a broad spectrum of curricula to meet their career stage goals and developmental needs.

We provide our colleagues what they need to learn and grow to be best-in-class client leaders.

From self-guided learning courses to advanced leadership programs, the curriculum is aligned to the Aon United strategy.

Our investment in technology and use of virtual and in-person based learning and development programs allows us to deliver targeted offerings designed to advance all colleagues’ development.

Providing an engaging and rewarding colleague experience is a top priority for us and understanding colleagues’ feedback helps us to reach that goal.

We use a variety of channels to facilitate open, on-going, and direct communication with colleagues.

Business Resource Groups are our independent and voluntary networks that provide input, take action, and help identify opportunities for our firm to further commitments to inclusion, wellbeing, and belonging.

*Inclusion*

We are focused on being a firm that is representative of the communities in which we operate.

We aim to achieve this by aligning inclusion actions to the following pillars: recruitment, education, promotion, and representation.

We strongly believe that only when colleagues can be their authentic selves will they reach their full potential.

The Company’s Board of Directors (“Board”) oversees Aon’s ERM program and allocates certain oversight responsibilities to its committees and any sub-committees, as appropriate.

Our Global Inclusive Leadership Council is sponsored by our Chief Executive Officer and Chief Administrative Officer.

At the manager level, 28% of senior leaders and 44% of managers with one or more direct report were women.

New colleague hires for the year in the U.S. were 30% racially or ethnically diverse.

*Apprenticeship Program*

| FOR THE FISCAL YEAR ENDED | | | | | | | | | DECEMBER 31, [removed: 2024] [added: 2025] | | |

| Guarantees of Aon plc’s [removed: 3.875%] [added: 4.250%] Senior Notes due [removed: 2025] [added: 2042] | | | | | | [removed: AON25] [added: AON42] | | | | | | New York Stock Exchange | | |

| Guarantees of Aon Corporation and Aon Global Holdings plc’s [removed: 2.85%] [added: 2.850%] Senior Notes due 2027 | | | | | | AON27 | | | | | | New York Stock Exchange | | |

| Guarantees of Aon Corporation and Aon Global Holdings plc’s [removed: 2.05%] [added: 2.050%] Senior Notes due 2031 | | | | | | AON31 | | | | | | New York Stock Exchange | | |

| Guarantees of Aon Corporation and Aon Global Holdings plc’s [removed: 2.60%] [added: 2.600%] Senior Notes due 2031 | | | | | | AON31A | | | | | | New York Stock Exchange | | |

| Guarantees of Aon Corporation and Aon Global Holdings plc’s [removed: 5.00%] [added: 5.000%] Senior Notes due 2032 | | | | | | AON32 | | | | | | New York Stock Exchange | | |

| Guarantees of Aon Corporation and Aon Global Holdings plc’s [removed: 5.35%] [added: 5.350%] Senior Notes due 2033 | | | | | | AON33 | | | | | | New York Stock Exchange | | |

| Guarantees of Aon plc’s [removed: 4.25%] [added: 4.450%] Senior Notes due [removed: 2042] [added: 2043] | | | | | | [removed: AON42] [added: AON43] | | | | | | New York Stock Exchange | | |

| Guarantees of Aon plc’s [removed: 4.45%] [added: 4.600%] Senior Notes due [removed: 2043] [added: 2044] | | | | | | [removed: AON43] [added: AON44] | | | | | | New York Stock Exchange | | |

| Guarantees of Aon plc’s [removed: 4.60%] [added: 4.750%] Senior Notes due [removed: 2044] [added: 2045] | | | | | | [removed: AON44] [added: AON45] | | | | | | New York Stock Exchange | | |

| Guarantees of Aon [added: Corporation and Aon Global Holdings] plc’s [removed: 4.75%] [added: 2.900%] Senior Notes due [removed: 2045] [added: 2051] | | | | | | [removed: AON45] [added: AON51] | | | | | | New York Stock Exchange | | |

| Guarantees of Aon Corporation and Aon Global Holdings plc’s [removed: 2.90%] [added: 3.900%] Senior Notes due [removed: 2051] [added: 2052] | | | | | | [removed: AON51] [added: AON52] | | | | | | New York Stock Exchange | | |

As of June [removed: 28, 2024,] [added: 30, 2025,] the aggregate market value of the registrant’s Class A Ordinary Shares held by non-affiliates of the registrant was [removed: $63,751,112,781] [added: $76,965,213,677] based on the closing sales price as reported on the New York Stock Exchange — Composite Transaction Listing.

Number of the registrant’s Class A Ordinary Shares of Aon plc, $0.01 nominal value, outstanding as of February [removed: 14, 2025: 216,001,106.][added: 12, 2026: 214,254,496.]

Portions of the registrant’s proxy statement for its [removed: 2025] [added: 2026] Annual General Meeting of Shareholders are incorporated by reference in this report in response to Part III, Items 10, 11, 12, 13, and 14.

Forward-looking statements are typically identified by words such as “anticipate,” “believe,” “estimate,” “expect,” “forecast,” “project,” “positioned,” “intend,” “plan,” “probably,” “potential,” “looking forward,” “continue,” [added: “ensure,” “commit,” “target,”] and other similar terms, and future or conditional tense verbs like “could,” “may,” “might,” “should,” “will,” and “would.” You can also identify forward-looking statements by the fact that they do not relate strictly to historical or current facts.

For example, we may use forward-looking statements when addressing topics such as: market and industry conditions, including competitive and pricing trends; changes in our business strategies and methods of generating revenue; the development and performance of our services and products; changes in the composition or level of our revenues; our cost structure and the outcome of cost-saving or restructuring initiatives, including the impacts of the Accelerating Aon United Program; [added: the] outcome of contingencies; dividend policy; the expected impact of acquisitions, dispositions, and other significant transactions or the termination thereof; litigation and regulatory matters; pension obligations; cash flow and liquidity; expected effective tax rate; expected foreign currency translation impacts; potential changes in laws or future actions by regulators; and the impact of changes in accounting rules.

- changes in the competitive environment, due to macroeconomic conditions [removed: (including impacts from instability in the banking] or [removed: commercial real estate sectors) or] otherwise, or damage to our reputation;

- the impact of, and potential challenges in complying with, laws and regulations of the jurisdictions in which we operate, particularly given the global nature of [added: our] operations and the possibility of differing or conflicting laws and regulations, or the application or interpretation thereof, across such [removed: jurisdictions;][added: jurisdictions, including but not limited to in the areas of cybersecurity, data privacy, and artificial intelligence;]

- the effects of Irish law on our operating flexibility and the enforcement of judgments against us; [added: and]

- adverse effects on the market price of Aon’s securities and/or operating results for any reason, including, without limitation, because of a failure to realize the expected benefits of the acquisition of [removed: NFP] [added: NFP,] (including anticipated revenue and growth synergies) in the expected timeframe, or at [removed: all; and][added: all.]

| | | | [Item 1. [removed: Business](#i00244c839c4944c8a8047ee0e04c19c6_19)] [added: Business](#i5df6841a42114b02bee2e85862920475_19)] | | |

| | | | [Item 1A. Risk [removed: Factors](#i00244c839c4944c8a8047ee0e04c19c6_22)] [added: Factors](#i5df6841a42114b02bee2e85862920475_22)] | | |

| | | | [Item 1B. Unresolved Staff [removed: Comments](#i00244c839c4944c8a8047ee0e04c19c6_25)] [added: Comments](#i5df6841a42114b02bee2e85862920475_25)] | | |

| | | | [Item 1C. [removed: Cybersecurity](#i00244c839c4944c8a8047ee0e04c19c6_28)] [added: Cybersecurity](#i5df6841a42114b02bee2e85862920475_28)] | | |

| | | | [Item 2. [removed: Properties](#i00244c839c4944c8a8047ee0e04c19c6_31)] [added: Properties](#i5df6841a42114b02bee2e85862920475_31)] | | |

| | | | [Item 3. Legal [removed: Proceedings](#i00244c839c4944c8a8047ee0e04c19c6_34)] [added: Proceedings](#i5df6841a42114b02bee2e85862920475_34)] | | |

| | | | [Item 4. Mine Safety [removed: Disclosure](#i00244c839c4944c8a8047ee0e04c19c6_37)] [added: Disclosure](#i5df6841a42114b02bee2e85862920475_37)] | | |

| | | | [Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity [removed: Securities](#i00244c839c4944c8a8047ee0e04c19c6_46)] [added: Securities](#i5df6841a42114b02bee2e85862920475_46)] | | |

| | | | [Item 6. [removed: \[Reserved\]](#i00244c839c4944c8a8047ee0e04c19c6_49)] [added: \[Reserved\]](#i5df6841a42114b02bee2e85862920475_49)] | | |

| | | | [Item 7. Management's Discussion and Analysis of Financial Condition and Results of [removed: Operations](#i00244c839c4944c8a8047ee0e04c19c6_52)] [added: Operations](#i5df6841a42114b02bee2e85862920475_52)] | | |

| | | | [Item 7A. Quantitative and Qualitative Disclosures About Market [removed: Risk](#i00244c839c4944c8a8047ee0e04c19c6_70)] [added: Risk](#i5df6841a42114b02bee2e85862920475_70)] | | |

| | | | [Item 8. Financial Statements and Supplementary [removed: Data](#i00244c839c4944c8a8047ee0e04c19c6_73)] [added: Data](#i5df6841a42114b02bee2e85862920475_73)] | | |

| | | | [Aon plc Consolidated Statements of [removed: Income](#i00244c839c4944c8a8047ee0e04c19c6_76)] [added: Income](#i5df6841a42114b02bee2e85862920475_76)] | | |

| | | | [Aon plc Consolidated Statements of Comprehensive [removed: Income](#i00244c839c4944c8a8047ee0e04c19c6_79)] [added: Income](#i5df6841a42114b02bee2e85862920475_79)] | | |

| | | | [Aon plc Consolidated Statements of Financial [removed: Position](#i00244c839c4944c8a8047ee0e04c19c6_82)] [added: Position](#i5df6841a42114b02bee2e85862920475_82)] | | |

| | | | [Aon plc Consolidated Statements of Shareholders' [removed: Equity](#i00244c839c4944c8a8047ee0e04c19c6_85)] [added: Equity](#i5df6841a42114b02bee2e85862920475_85)] | | |

| | | | [Aon plc Consolidated Statements of Cash [removed: Flows](#i00244c839c4944c8a8047ee0e04c19c6_88)] [added: Flows](#i5df6841a42114b02bee2e85862920475_88)] | | |

| | | | [Notes to Consolidated Financial [removed: Statements](#i00244c839c4944c8a8047ee0e04c19c6_91)] [added: Statements](#i5df6841a42114b02bee2e85862920475_91)] | | |

| | | | [Item 9. Changes in and Disagreements with Accountants on Accounting and Financial [removed: Disclosure](#i00244c839c4944c8a8047ee0e04c19c6_145)] [added: Disclosure](#i5df6841a42114b02bee2e85862920475_145)] | | |

- international risks associated with our global operations, including geopolitical conflicts, tariffs, or changes in trade policies;

| [PART I](#i5df6841a42114b02bee2e85862920475_16) | | | | | |

| [PART II](#i5df6841a42114b02bee2e85862920475_43) | | | | | |

| ASC | | | Accounting Standards Codification | | |

| EMEA | | | Europe, the Middle East, and Africa | | |

| GCS | | | Global Cybersecurity Services | | |

| Guarantees of Aon Corporation and Aon Global Holdings plc’s 3.90% Senior Notes due 2052 | | | | | | AON52 | | | | | | New York Stock Exchange | | |

- international risks associated with our global operations, including impacts from military conflicts or political instability, such as the ongoing Russian war in Ukraine and the conflicts in the Middle East;

- significant integration costs in connection with the acquisition of NFP or unknown or inestimable liabilities.

| | | | | | |

| [PART I](#i00244c839c4944c8a8047ee0e04c19c6_16) | | | | | |

| [PART II](#i00244c839c4944c8a8047ee0e04c19c6_43) | | | | | |

| ESG | | | Environmental, Social, Corporate Governance | | |

| GSS | | | Global Security Services | | |

| NFP | | | National Financial Partners | | |

Aon’s management carries out the [added: daily] processes, controls, and practices of the Company’s ERM program, [added: many of which are embedded within our operations,] including the identification, assessment, prioritization, and mitigation of cybersecurity risks.

[added: The Audit Committee also has primary responsibility for the oversight of] cybersecurity risk and engages in regular discussion with management regarding cybersecurity and privacy risk mitigation and incident [removed: management.][added: management, including risks arising from the use of artificial intelligence.]

The Company’s management, including the Chief [added: Information] Security Officer [removed: (“CSO”),] [added: (“CISO”),] regularly presents [added: (no less than twice annually)] to the Audit Committee of the Board regarding cybersecurity matters.

In addition, Aon maintains a Global [removed: Security] [added: Cybersecurity] Services [removed: (“GSS”)] [added: (“GCS”)] organization, led by the [removed: CSO,] [added: CISO,] with dedicated [removed: security] [added: cybersecurity] personnel responsible for protecting Aon’s [removed: people, property,] [added: information] and [removed: information.][added: information systems.]

Aon’s [removed: CSO] [added: CISO] reports to Aon’s Chief Operating Officer and is an experienced [removed: technology and] cybersecurity professional, with over [removed: 20] [added: 15] years’ experience in information [removed: security and technology.][added: security.]

In coordination with the Global Privacy [added: & Data Trust] Office [removed: (“GPO”)] [added: (“GPDTO”)] and [removed: GSS,] [added: GCS,] the GEOC reports significant cybersecurity incidents to the Cyber Incident Governance Committee (“CIGC”).

The CIGC includes the [removed: CSO,] [added: CISO,] the Chief Privacy and Data Trust Officer, and other representatives from the Company’s [removed: GPO] [added: GPDTO] and [removed: GSS,] [added: GCS,] as well as leaders from the Company’s operations, Risk Management, Law & Compliance, Controllership, Internal Audit, and Communications functions.

Aon’s [removed: GPO] [added: GPDTO] and Law & Compliance department work with business units to incorporate appropriate controls into supplier contracts.

We also maintain insurance to provide protection against certain losses that may be associated with a cybersecurity breach or data privacy event, although our coverage may not be sufficient to offset all losses arising from such events.

The Audit Committee also has primary responsibility for the oversight of

We maintain our corporate headquarters at 15 George's Quay, Dublin 2, Ireland, where we occupy approximately [removed: 33,000] [added: 29,000] square feet of space under an operating lease agreement that expires in 2044.

| 165 Broadway, New York, New York | | | [removed: 217,000] [added: 204,000] | | | | | | 2028 | | |

[added: See Note 9 “Lease Commitments” of the Notes] to Consolidated Financial Statements in Part II, Item 8 of this report for information with respect to our lease commitments as of December 31, [removed: 2024.][added: 2025.]

See Note 9 “Lease Commitments” of the Notes

The executive officers of Aon, as of February [removed: 18, 2025] [added: 13, 2026] unless otherwise noted, their business experience during a period of the last five years or longer, and their ages and positions held are set forth below.

| Gregory C. Case | | | | | | [removed: 62] [added: 63] | | | | | | [added: President and] Chief Executive Officer. Mr. Case became Chief Executive Officer of Aon in April [removed: 2005. He also served as Aon’s President from April] 2005 [removed: to May 2018.] [added: and assumed the additional title of President in March 2025.] Prior to joining Aon, Mr. Case was a partner with McKinsey & Company, a global management consulting firm, for 17 years, most recently serving as head of the Financial Services Practice. He previously was responsible for McKinsey’s Global Insurance Practice and was a member of McKinsey’s governing Shareholders’ [removed: Committee.] [added: Council.] Prior to joining McKinsey, Mr. Case worked for the investment banking firm of Piper, Jaffray and Hopwood and the Federal Reserve Bank of Kansas City. | | |

| Edmund Reese | | | | | | [removed: 50] [added: 51] | | | | | | Chief Financial Officer. Mr. Reese became Chief Financial Officer of the Company in July 2024. Prior to joining Aon, Mr. Reese served as the Corporate Vice President, Chief Financial Officer of Broadridge Financial Solutions, Inc., a financial technology and services provider, since 2020. Mr. Reese joined Broadridge from American Express Company, a bank holding company and financial services provider, where he most recently served as Senior Vice President and CFO of the Global Consumer Services Group since April 2019. | | |

| Mindy Simon | | | | | | [removed: 48] [added: 49] | | | | | | Chief Operating Officer. Ms. Simon joined Aon as Chief Operating Officer in October 2022. Prior to joining Aon, Ms. Simon served as Chief Information Officer for Conagra Brands since June 2017. Prior to her role as Chief Information Officer, Ms. Simon held a variety of roles in finance and information technology with Conagra Brands since joining the company in 2000, including serving as VP Global Business Services from January 2016 to June 2017, and VP Information Technology from 2008 to 2016. | | |

| Lisa Stevens | | | | | | [removed: 54] [added: 55] | | | | | | Chief Administrative Officer. Ms. Stevens joined Aon in December 2018 as Global Executive Vice President and was named as Chief People Officer in October 2019 and Chief Administrative Officer in July 2024. Prior to joining Aon, Ms. Stevens held a variety of roles during her 29-year career at Wells Fargo, most recently as Executive Vice President where she led the Western Region for the Community Bank. | | |

| Darren Zeidel | | | | | | [removed: 53] [added: 54] | | | | | | General Counsel and Company Secretary. Mr. Zeidel was named General Counsel and Company Secretary in July 2019. Prior to this Mr. Zeidel held several leadership roles with Aon, including as Deputy General Counsel immediately prior to his appointment; Global Chief Counsel - Corporate, Retirement & Investment and Health Exchanges from 2017 to 2019; and Global Chief Counsel of Aon Hewitt upon joining Aon in 2012 to 2017. Before this Mr. Zeidel worked for Honeywell, where he held business segment general counsel roles in the aerospace strategic business unit and at Honeywell UOP LLC. Mr. Zeidel began his career as an Associate in the Mergers and Acquisitions group in the New York office of Skadden, Arps, Slate, Meagher & [removed: Flom,] [added: Flom] LLP. | | |

| Anne Corona | | | | | | 48 | | | | | | CEO, Enterprise Clients and Global Chief Commercial Officer. Ms. Corona was named Chief Executive Officer, Enterprise Clients and Global Chief Commercial Officer in December 2024. Ms. Corona previously held several leadership roles since joining Aon in 2000, including CEO, Asia Pacific immediately prior to her appointment; President of Aon’s Financial Services Group; and Chief of Staff for the office of the global CEO. | | |

| David DeBrunner | | | | | | 59 | | | | | | Chief Accounting Officer and Global Controller. Mr. DeBrunner joined Aon as Chief Accounting Officer and Global Controller in September 2025. Before joining Aon, Mr. DeBrunner served as Vice President, Controller and Chief Accounting Officer of Ally Financial Inc., a bank holding company. Prior to joining Ally, Mr. DeBrunner was Senior Vice President and Corporate Controller at Fifth Third Bancorp. | | |

| Lori Goltermann | | | | | | 59 | | | | | | CEO, Regions and North America. Ms. Goltermann became CEO, Regions and North America in March 2024. Ms. Goltermann previously held a variety of roles at Aon since joining in 1993, including CEO, Global Enterprise Clients, and CEO of Aon’s U.S. Commercial Risk and Health Solutions businesses; and CEO, U.S. Health Solutions practice. | | |

| Andy Marcell | | | | | | 58 | | | | | | CEO, Global Solutions. Mr. Marcell was named Chief Executive Officer, Global Solutions, in June 2025. Prior to this Mr. Marcell held several leadership roles since joining Aon in 2015, including as CEO of Global Reinsurance Solutions from 2018 to 2023, and as CEO of Risk Capital from 2023 until June 2025. | | |

| Eric Andersen | | | | | | 60 | | | | | | President. Mr. Andersen joined Aon in 1997 upon the completion of the acquisition of Minet. Mr. Andersen has served in a variety of roles during his more than 20 year career at Aon, including as Chief Executive Officer of Aon Risk Solutions Americas from 2011 to 2013, and Chief Executive Officer of Aon Benfield from September 2013 to May 2018. Mr. Andersen was appointed Co-President of the Company in May 2018 and became President in February 2020. He was named an Executive Officer in February 2017. | | |

| Michael Neller | | | | | | 46 | | | | | | Chief Accounting Officer and Global Controller. Mr. Neller joined Aon in August 2011 as its Vice President, Technical Accounting and Policy. From December 2011 to February 2018, Mr. Neller served as Aon’s Deputy Global Controller. In this role, he was responsible for Aon’s Latin America and North America regions, as well as global accounting policy, corporate accounting, and external reporting. Before joining Aon, Mr. Neller served from July 2009 to August 2011 as a Senior Manager of KPMG LLP, an international public accounting firm, in its Department of Professional Practice (National Office). He was named Senior Vice President and Global Controller in February 2018. | | |

In February [removed: 2025,] [added: 2026,] Aon paid a quarterly cash dividend of [removed: $0.675] [added: $0.745] per share.

On February [removed: 14, 2025] [added: 12, 2026] the last reported sale price of our ordinary shares as reported by the NYSE was [removed: $386.99] [added: $314.49] per share.

We have approximately [removed: 483] [added: 448] holders of record of our class A ordinary shares as of February [removed: 18, 2025.][added: 12, 2026.]

We did not make any unregistered sales of equity in [removed: 2024.][added: 2025.]

| 10/1/25 – 10/31/25 | | | | | | 236,345 | | | | | | $ | 352.58 | | | | | 236,345 | | | | | | $ | 1,483,944,827 | |

| 11/1/25 – 11/30/25 | | | | | | 222,500 | | | | | | $ | 347.58 | | | | | 222,500 | | | | | | $ | 1,406,609,003 | |

| 12/1/25 – 12/31/25 | | | | | | 256,373 | | | | | | $ | 348.45 | | | | | 256,373 | | | | | | $ | 1,317,276,106 | |

| | | | | | | 715,218 | | | | | | $ | 349.54 | | | | | 715,218 | | | | | | $ | 1,317,276,106 | |

| 10/1/24 – 10/31/24 | | | | | | 279,120 | | | | | | $ | 357.83 | | | | | 279,120 | | | | | | $ | 2,413,804,583 | |

| 11/1/24 – 11/30/24 | | | | | | 183,058 | | | | | | $ | 380.52 | | | | | 183,058 | | | | | | $ | 2,344,147,491 | |

| 12/1/24 – 12/31/24 | | | | | | 71,057 | | | | | | $ | 378.27 | | | | | 71,057 | | | | | | $ | 2,317,269,118 | |

| | | | | | | 533,235 | | | | | | $ | 368.34 | | | | | 533,235 | | | | | | $ | 2,317,269,118 | |

We have audited the accompanying consolidated statements of financial position of Aon plc (the Company) as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] the related consolidated statements of income, comprehensive income, [removed: shareholders’] [added: shareholders'] equity [removed: (deficit)] and cash flows for each of the three years in the period ended December 31, [removed: 2024,] [added: 2025,] and the related notes (collectively referred to as the “consolidated financial statements”).

In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] and the results of its operations and its cash flows for each of the three years in the period ended December 31, [removed: 2024,] [added: 2025,] in conformity with U.S. generally accepted accounting principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, [removed: 2024,] [added: 2025,] based on criteria established in Internal [removed: Control-Integrated] [added: Control—Integrated] Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework), and our report dated February [removed: 18, 2025] [added: 13, 2026] expressed an unqualified opinion thereon.

Critical Audit [removed: Matters][added: Matter]

The critical audit [removed: matters] [added: matter] communicated below [removed: are matters] [added: is a matter] arising from the current period audit of the financial statements that [removed: were] [added: was] communicated or required to be communicated to the audit committee and that: (1) [removed: relate] [added: relates] to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments.

The communication of [added: the] critical audit [removed: matters] [added: matter] does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit [removed: matters] [added: matter] below, providing [added: a] separate [removed: opinions] [added: opinion] on the critical audit [removed: matters] [added: matter] or on the [removed: accounts] [added: account] or [removed: disclosures] [added: disclosure] to which [removed: they relate.][added: it relates.]

| *Description of the Matter* | | | As discussed in Note 10 “Income Taxes” of the Notes to Consolidated Financial Statements, the Company had gross deferred tax assets of $2,570 million at December 31, [removed: 2024.] [added: 2025.] Deferred tax assets are reduced by a valuation allowance if, based on the weight of all available evidence, in management’s judgment it is more likely than not that some portion, or all, of the deferred tax assets will not be realized. Conclusions on the realizability of certain net deferred tax assets involve significant management judgement including assumptions and estimates related to the amount, timing and jurisdiction of future taxable income. Auditing the deferred tax asset [removed: calculation] and the related forecast of future taxable income was especially challenging as it involved a high degree of auditor judgement around management’s assumptions and estimates of future taxable income. | | | | | | | | | | | |

][added: Signature_2022.jpg](https://www.sec.gov/Archives/edgar/data/315293/000162828026008116/aon-20251231_g1.jpg)]

| (millions, except per share data) | | | | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | |

| Total revenue | | | | | | $ | [removed: 15,698] [added: 17,181] | | | | | $ | [removed: 13,376] [added: 15,698] | | | | | $ | [removed: 12,479] [added: 13,376] | |

| Compensation and benefits | | | | | | [removed: 8,283] [added: 8,985] | | | | | | [removed: 6,902] [added: 8,283] | | | | | | [removed: 6,477] [added: 6,902] | | |

| Information technology | | | | | | [removed: 539] [added: 568] | | | | | | [removed: 534] [added: 539] | | | | | | [removed: 509] [added: 534] | | |

| Premises | | | | | | [removed: 325] [added: 337] | | | | | | [removed: 294] [added: 325] | | | | | | [removed: 289] [added: 294] | | |

| Depreciation of fixed assets | | | | | | [removed: 183] [added: 188] | | | | | | [removed: 167] [added: 183] | | | | | | [removed: 151] [added: 167] | | |

| Amortization and impairment of intangible assets | | | | | | [removed: 503] [added: 778] | | | | | | [removed: 89] [added: 503] | | | | | | [removed: 113] [added: 89] | | |

| Other general expense | | | | | | [removed: 1,641] [added: 1,616] | | | | | | [removed: 1,470] [added: 1,641] | | | | | | [removed: 1,271] [added: 1,470] | | |

| Accelerating Aon United Program expenses | | | | | | [removed: 389] [added: 365] | | | | | | [removed: 135] [added: 389] | | | | | | [removed: —] [added: 135] | | |

| Total operating expenses | | | | | | [removed: 11,863] [added: 12,837] | | | | | | [removed: 9,591] [added: 11,863] | | | | | | [removed: 8,810] [added: 9,591] | | |

| Operating income | | | | | | [removed: 3,835] [added: 4,344] | | | | | | [removed: 3,785] [added: 3,835] | | | | | | [removed: 3,669] [added: 3,785] | | |

| Interest income | | | | | | [removed: 67] [added: 19] | | | | | | [removed: 31] [added: 67] | | | | | | [removed: 18] [added: 31] | | |

| Interest expense | | | | | | [removed: (788)] [added: (815)] | | | | | | [removed: (484)] [added: (788)] | | | | | | [removed: (406)] [added: (484)] | | |

| Other income (expense) | | | | | | [removed: 348] [added: 1,211] | | | | | | [removed: (163)] [added: 348] | | | | | | [removed: (125)] [added: (163)] | | |

| Income before income taxes | | | | | | [removed: 3,462] [added: 4,759] | | | | | | [removed: 3,169] [added: 3,462] | | | | | | [removed: 3,156] [added: 3,169] | | |

| Income tax expense | | | | | | [removed: 742] [added: 1,009] | | | | | | [removed: 541] [added: 742] | | | | | | [removed: 510] [added: 541] | | |

| Net income | | | | | | [removed: 2,720] [added: 3,750] | | | | | | [removed: 2,628] [added: 2,720] | | | | | | [removed: 2,646] [added: 2,628] | | |

| Less: Net income attributable to redeemable and nonredeemable noncontrolling interests | | | | | | [removed: 66] [added: 55] | | | | | | [removed: 64] [added: 66] | | | | | | [removed: 57] [added: 64] | | |

| Net income attributable to Aon shareholders | | | | | | $ | [removed: 2,654] [added: 3,695] | | | | | $ | [removed: 2,564] [added: 2,654] | | | | | $ | [removed: 2,589] [added: 2,564] | |

| Basic net income per share attributable to Aon shareholders | | | | | | $ | [removed: 12.55] [added: 17.11] | | | | | $ | [removed: 12.60] [added: 12.55] | | | | | $ | [removed: 12.23] [added: 12.60] | |

| Diluted net income per share attributable to Aon shareholders | | | | | | $ | [removed: 12.49] [added: 17.02] | | | | | $ | [removed: 12.51] [added: 12.49] | | | | | $ | [removed: 12.14] [added: 12.51] | |

| Weighted average ordinary shares outstanding - basic | | | | | | [removed: 211.4] [added: 215.9] | | | | | | [removed: 203.5] [added: 211.4] | | | | | | [removed: 211.7] [added: 203.5] | | |

| Weighted average ordinary shares outstanding - diluted | | | | | | [removed: 212.5] [added: 217.1] | | | | | | [removed: 205.0] [added: 212.5] | | | | | | [removed: 213.2] [added: 205.0] | | |

| (millions) | | | | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | |

| Net income | | | | | | $ | [removed: 2,720] [added: 3,750] | | | | | $ | [removed: 2,628] [added: 2,720] | | | | | $ | [removed: 2,646] [added: 2,628] | |

| Net income attributable to Aon shareholders | | | | | | [removed: 2,654] [added: 3,695] | | | | | | [removed: 2,564] [added: 2,654] | | | | | | [removed: 2,589] [added: 2,564] | | |

| Change in fair value of financial instruments | | | | | | [removed: 72] [added: 4] | | | | | | [removed: 13] [added: 72] | | | | | | [removed: (13)] [added: 13] | | |

| Foreign currency translation adjustments | | | | | | [removed: (467)] [added: 826] | | | | | | [removed: 276] [added: (467)] | | | | | | [removed: (528)] [added: 276] | | |

| Postretirement benefit obligation | | | | | | [removed: 23] [added: 72] | | | | | | [removed: (40)] [added: 23] | | | | | | [removed: (211)] [added: (40)] | | |

| Total other comprehensive income [removed: (loss)] [added: (expense)] | | | | | | [removed: (372)] [added: 902] | | | | | | [removed: 249] [added: (372)] | | | | | | [removed: (752)] [added: 249] | | |

| Less: Other comprehensive loss attributable to noncontrolling interests | | | | | | — | | | | | | [removed: (1)] [added: —] | | | | | | [removed: —] [added: (1)] | | |

| Total other comprehensive income [removed: (loss)] [added: (expense)] attributable to Aon shareholders | | | | | | [removed: (372)] [added: 902] | | | | | | [removed: 250] [added: (372)] | | | | | | [removed: (752)] [added: 250] | | |

February 13, 2026

| Less: Net income attributable to redeemable and nonredeemable noncontrolling interests | | | | | | 55 | | | | | | 66 | | | | | | 64 | | |

| Adjustments to redeemable noncontrolling interest | | | | | | — | | | | | | (3) | | | | | | — | | | | | | — | | | | | | — | | | | | | (3) | | |

| Net income (1) | | | | | | — | | | | | | — | | | | | | 3,695 | | | | | | — | | | | | | 59 | | | | | | 3,754 | | |

| Shares repurchased | | | | | | (2.7) | | | | | | — | | | | | | (1,000) | | | | | | — | | | | | | — | | | | | | (1,000) | | |

| Balance at December 31, 2025 | | | | | | 214.5 | | | | | | $ | 13,440 | | | | | $ | (245) | | | | | $ | (3,843) | | | | | $ | 107 | | | | | $ | 9,459 | |

| Depreciation of fixed assets | | | | | | 188 | | | | | | 183 | | | | | | 167 | | |

| Amortization and impairment of intangible assets | | | | | | 778 | | | | | | 503 | | | | | | 89 | | |

*Commercial Risk Solutions* uses Risk Capital’s extensive data and analytics capabilities to provide brokerage and consulting services that help organizations develop, improve, and implement their risk management strategies.

| Vehicles | | | | | | 5 to 6 years | | |

When Aon holds rights that give it the power to direct the activities of a VIE that most significantly impact the

The adoption of this guidance impacted the Company’s Notes to Consolidated Financial Statements and did not impact the financial condition or results of operations.

See Note 10 “Income Taxes” for information with respect to this guidance as of December 31, 2025.

*Accounting for and Disclosure of Software Costs*

In September 2025, the FASB issued new accounting guidance under ASC 350-40, *Intangibles — Goodwill and Other Internal-Use Software* to modernize the criteria for capitalizing software development costs by removing references to development stages and framework updates to better reflect current software development practices.

The new guidance is effective for annual periods beginning after December 15, 2027, with early adoption permitted.

emissions.

On March 27, 2025, the SEC voted to end its legal defense of the final rules in Court of Appeals for the Eighth Circuit.

The Eighth Circuit has suspended the litigation until the SEC informs the court whether it intends to reconsider the rules under administrative procedures or whether the SEC will renew its defense of the rules.

The Company is monitoring the judicial process for resolution of the legal challenges and impacts on the disclosure requirements.

| Total revenue | | | | | | $ | 17,181 | | | | | $ | 15,698 | | | | | $ | 13,376 | |

| U.S. | | | | | | $ | 4,991 | | | | | $ | 3,304 | | | | | $ | (16) | | | | | $ | 8,279 | |

| U.K. | | | | | | 1,409 | | | | | | 811 | | | | | | — | | | | | | 2,220 | | |

| Asia Pacific | | | | | | 1,343 | | | | | | 368 | | | | | | — | | | | | | 1,711 | | |

| Total revenue | | | | | | $ | 11,290 | | | | | $ | 5,907 | | | | | $ | (16) | | | | | $ | 17,181 | |

| | | | | | | 2025 | | | | | | 2024 | | |

| | | | | | | 2025 | | | | | | 2024 | | |

| | | | | | | 2025 | | | | | | 2024 | | |

| Charges | | | 195 | | | | | | 155 | | | | | | 15 | | | | | | 365 | | |

| Cash payments | | | (165) | | | | | | (132) | | | | | | — | | | | | | (297) | | |

| Liability balance as of December 31, 2025 | | | $ | 39 | | | | | $ | 108 | | | | | $ | — | | | | | $ | 147 | |

(1)The gain from the disposal of the NFP Wealth business for the year ended December 31, 2025 was $1,199 million.

| Other (2) | | | 190 | | | | | | 157 | | |

(2)Includes $1 million as of December 31, 2024 that was previously classified as “Assets held for sale” within Aon’s Annual Report on Form 10-K filed February 18, 2025.

| Other (2)(3) | | | 274 | | | | | | 611 | | |

The prior year balance has been reclassified to conform to current year presentation.

(3)As of December 31, 2024, includes $416 million of consideration paid into an escrow account related to the acquisition of Griffiths & Armour, which closed on January 1, 2025.

Refer to Note 6 “Acquisitions and Dispositions of Businesses” for additional information.

On January 1, 2025, the Company completed the acquisition of 100% of partnership interests and share capital of Griffiths & Armour, an insurance broker in the United Kingdom for a purchase price of approximately $426 million, in the Risk Capital segment.

Total acquisitions completed by the Company for the year ended December 31, 2025 and 2024 were as follows.

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| | | | Valuation of customer relationship intangible assets in the acquisition of NFP | | | | | | | | | | | |

| *Description of the Matter* | | | As discussed in Note 6 “Acquisitions and Disposition of Businesses” of the Notes to Consolidated Financial Statements, the Company acquired NFP Intermediate Holdings A Corp (also referred to as “NFP”) on April 25, 2024. The transaction was accounted for under the acquisition method of accounting. The Company preliminarily determined the fair value of the identified customer relationship intangible assets to be $5,950 million. The fair value was estimated based on a multi-period excess earnings method of the income approach and used financial projections developed by management applying market participant assumptions. Auditing the Company’s accounting for certain of the acquired customer relationship intangible assets was complex due to estimation uncertainty in the Company’s preliminary determination of the fair value. The estimation uncertainty was primarily due to the sensitivity of the fair value of certain of the customer relationship intangible assets to underlying assumptions about the future performance of the acquired business. The significant assumptions used to estimate the fair value included EBITA margin and discount rate. These significant assumptions are forward looking and could be affected by future economic and market conditions. | | | | | | | | | | | |

| *How We Addressed the Matter in Our Audit* | | | We obtained an understanding of the Company’s process for evaluating the valuation of acquired customer relationship intangible assets. We tested the design and operating effectiveness of the Company's controls over the estimation process supporting the measurement and recognition of customer relationship intangible assets. We also tested controls regarding management’s review of assumptions used in the valuation model. To test the estimated fair value of the Company’s customer relationship intangible assets, we performed, with the assistance of our valuation specialists, audit procedures that included evaluating the Company’s valuation methodology, significant assumptions used and completeness and accuracy of the underlying data. For example, we compared the significant assumptions to historical and current industry, market and economic trends. We also tested the underlying source information used and verified the mathematical accuracy of the calculations within the valuation model. | | | | | | | | | | | |

February 18, 2025

| Balance at January 1, 2022 | | | | | | 214.8 | | | | | | 6,626 | | | | | | (1,694) | | | | | | (3,871) | | | | | | 97 | | | | | | 1,158 | | |

| Net income | | | | | | — | | | | | | — | | | | | | 2,589 | | | | | | — | | | | | | 57 | | | | | | 2,646 | | |

| Shares repurchased | | | | | | (11.1) | | | | | | — | | | | | | (3,203) | | | | | | — | | | | | | — | | | | | | (3,203) | | |

| Supplemental disclosures: | | | | | | | | | | | | | | | | | | | | |

| Interest paid | | | | | | $ | 658 | | | | | $ | 446 | | | | | $ | 351 | |

Revenue from health care exchange arrangements is typically recognized upon successful enrollment of participants.

| Automobiles | | | | | | 6 years | | |

Finance leases are included in Other non-current assets, Other current liabilities, and Other non-current liabilities in the Consolidated Statements of Financial Position.

interest model.

*Improvements to Reportable Segment Disclosures*

In November 2023, the FASB issued new accounting guidance, requiring new segment disclosures under ASC 280, *Segment Reporting,* including disclosure of significant segment expense categories and amounts that are regularly reported to the CODM and included in the segment’s profit or loss in interim and annual periods.

The Company has adopted the new guidance effective December 31, 2024, on a retrospective basis for all periods presented and prior period comparative segment information has been recast to conform with current year presentation within Note 17 “Segment Information”.

The Company is currently evaluating the impact that the guidance will have on our disclosures and will monitor the judicial process for impacts on the disclosure requirements.

| U.S. | | | | | | $ | 3,910 | | | | | $ | 1,773 | | | | | $ | (17) | | | | | $ | 5,666 | |

| U.K. | | | | | | 1,068 | | | | | | 592 | | | | | | — | | | | | | 1,660 | | |

| Asia Pacific | | | | | | 1,160 | | | | | | 314 | | | | | | — | | | | | | 1,474 | | |

| Charges | | | 126 | | | | | | 197 | | | | | | 66 | | | | | | 389 | | |

| Cash payments | | | (96) | | | | | | (172) | | | | | | — | | | | | | (268) | | |

(1)For the year ended December 31, 2024, the Company recognized $27 million of accelerated ROU asset amortization or impairments due to the Company’s decision to exit certain leased properties as a result of the Program.

The amounts are presented in Technology and other, where the corresponding liability is reflected within Other current liabilities and Non-current operating lease liabilities, which will ultimately be settled in cash.

| | | | | | | | | | | | |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| Assets held for sale | | | 1 | | | | | | 354 | | |

| Other | | | 156 | | | | | | 137 | | |

| Leases (2) | | | 9 | | | | | | 26 | | |

| Other | | | 602 | | | | | | 140 | | |

(2) Refer to Note 9 “Lease Commitments” for further information.

| Liabilities held for sale | | | — | | | | | | 69 | | |

(1)There was no non-current transition tax as of December 31, 2024.

There was $72 million of non-current transition tax as of December 31, 2023.

Refer to Note 10 “Income Taxes” for further information on the transition tax.

On April 25, 2024 (the “Acquisition Date”), the Company completed the acquisition of NFP, a leading middle market property and casualty broker, benefits consultant, wealth manager, and retirement plan advisor, with more than 7,700 colleagues.

The Transaction expands Aon’s presence in the large and fast-growing middle-market and enhances NFP’s strong existing client relationships and distribution, by bringing Aon’s data and analytics-based content, capabilities, and expertise, delivered through the Aon Business Services platform.

Including the acquisition of NFP, the Company completed 22 acquisitions, 10 within Risk Capital and 12 within Human Capital, during the year ended December 31, 2024.

Total consideration transferred for these acquisitions was $9.6 billion.

We have conducted an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures, as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) as of the end of the period covered by this annual report of December 31, [removed: 2024.][added: 2025.]

Based on this evaluation, our Chief Executive Officer and Chief Financial Officer concluded as of December 31, [removed: 2024] [added: 2025] that our disclosure controls and procedures were effective [added: at a reasonable assurance level] such that the information relating to Aon, including our consolidated subsidiaries, required to be disclosed in our SEC reports is recorded, processed, summarized and reported within the time periods specified in SEC rules and forms, and is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate to allow timely decisions regarding required disclosure.

Under the supervision and with the participation of our senior management, including our Chief Executive Officer and Chief Financial Officer, we assessed the effectiveness of our internal control over financial reporting as of December 31, [removed: 2024.][added: 2025.]

In making this assessment, we used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in the *Internal Control — Integrated Framework* (2013 Framework)*.* Based on this assessment, management has concluded our internal control over financial reporting was effective as of December 31, [removed: 2024.][added: 2025.]

The effectiveness of our internal control over financial reporting as of December 31, [removed: 2024] [added: 2025] has been audited by Ernst & Young, LLP, the Company’s independent registered public accounting firm, as stated in their report included herein titled “Report of Independent Registered Public Accounting Firm-Opinion on Internal Control over Financial Reporting.”

There were no changes, [removed: other than the acquisition of NFP,] in our internal control over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act) that occurred during the quarter ended December 31, [removed: 2024] [added: 2025] that have materially affected, or that are reasonably likely to materially affect, our internal control over financial reporting.

We have audited Aon plc’s internal control over financial reporting as of December 31, [removed: 2024,] [added: 2025,] based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework) (the COSO criteria).

In our opinion, Aon plc (the Company) maintained, in all material respects, effective internal control over financial reporting as of December 31, [removed: 2024,] [added: 2025,] based on the COSO criteria.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated statements of financial position of the Company as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] the related consolidated statements of income, comprehensive income, [removed: shareholders'] [added: shareholders’] equity [removed: (deficit)] and cash flows for each of the three years in the period ended December 31, [removed: 2024,] [added: 2025,] and the related notes and our report dated February [removed: 18, 2025] [added: 13, 2026] expressed an unqualified opinion thereon.

][added: Signature_2022.jpg](https://www.sec.gov/Archives/edgar/data/315293/000162828026008116/aon-20251231_g1.jpg)]

February 13, 2026

On April 25, 2024, we completed our acquisition of NFP.

We are in the process of assessing NFP’s internal controls over financial reporting and will make appropriate changes as NFP is integrated into the our internal controls over financial reporting.

Management’s report on Internal Control Over Financial Reporting does not include the internal controls of NFP, which is included in the 2024 consolidated financial statements of the Company and constituted 3% of total assets, excluding the preliminary value of goodwill and other intangibles assets, as of December 31, 2024 and 11% of total revenue for the year then ended December 31, 2024.

As indicated in the accompanying Management’s Report on Internal Control Over Financial Reporting, management’s assessment of and conclusion on the effectiveness of internal control over financial reporting did not include the internal controls of NFP, which is included in the 2024 consolidated financial statements of the Company and constituted 3% of Total assets, excluding the preliminary value of Goodwill and Other intangible assets, as of December 31, 2024 and 11% of Total revenue for the year then ended.

Our audit of internal control over financial reporting of the Company also did not include an evaluation of the internal control over financial reporting of NFP.

February 18, 2025

On November 5, 2025, Darren Zeidel, Executive Vice President, General Counsel and Company Secretary, adopted a new Rule 10b5-1 trading plan intended to satisfy the affirmative defense in Rule 10b5-1(c).

The plan’s maximum length is until February 2, 2027 and first trades were not permitted to occur until February 3, 2026, at the earliest.

The plan is intended to permit Mr. Zeidel to sell 5,650 and 7,021 class A ordinary shares of Aon received pursuant to the vesting of certain equity awards, net of any shares withheld for taxes.

Not applicable.

Information relating to Aon’s directors is set forth under the heading “Proposal 1 — Resolutions Regarding the Election of Directors” in the Proxy Statement for the [removed: 2025] [added: 2026] Annual General Meeting of Shareholders (the “Proxy Statement”) and is incorporated herein by reference.

We have adopted a code of ethics that applies to the Company’s directors, officers, and employees, including the Chief Executive Officer, Chief Financial Officer, and [added: Global] Controller and Chief Accounting Officer and other persons performing similar functions.

We will disclose on our website any amendment to or waiver from our [removed: code] [added: Code] of [removed: ethics] [added: Business Conduct] on behalf of any of our executive officers or directors.

The other information required by this Item 10 is incorporated by reference to the definitive Proxy Statement for our 2026 Annual Meeting of Shareholders, which will be filed with the SEC no later than 120 days after December 31, 2025.

Information relating to compensation committee interlocks and insider participation is set forth under the heading [removed: “Compensation Discussion and Analysis -] [added: “Corporate Governance —] Compensation Committee Interlocks and Insider Participation” in the Proxy Statement and is incorporated herein by reference.

Information relating to equity compensation plans and the security ownership of certain beneficial owners and management of Aon plc’s ordinary shares is set forth under the headings “Other Information [removed: -] [added: —] Equity Compensation Plan Information,” “Principal Holders of Voting Securities,” and “Security Ownership of Directors and Executive Officers” in the Proxy Statement, and all such information is incorporated herein by reference.

| | | | Consolidated Statements of Financial Position — As of December 31, [removed: 2024] [added: 2025] and [removed: 2023] [added: 2024] | | | | | |

| | | | Consolidated Statements of Income — Years Ended December 31, [added: 2025,] 2024, [removed: 2023,] and [removed: 2022] [added: 2023] | | | | | |

| | | | Consolidated Statements of Comprehensive Income — Years Ended December 31, [added: 2025,] 2024, [removed: 2023,] and [removed: 2022] [added: 2023] | | | | | |

| | | | Consolidated Statements of Shareholders’ Equity — Years Ended December 31, [added: 2025,] 2024, [removed: 2023,] and [removed: 2022] [added: 2023] | | | | | |

| | | | Consolidated Statements of Cash Flows — Years Ended December 31, [added: 2025,] 2024, [removed: 2023,] and [removed: 2022] [added: 2023] | | | | | |

| | | | | | | [removed: 4.11*] [added: 4.12*] | | | [Form of [removed: 3.875%] [added: 4.500%] Senior Note due [removed: 2025] [added: 2028] - incorporated by reference to Exhibit [removed: 1.1] [added: 4.2] to Aon’s Current Report on Form 8-K filed [removed: on February 29, 2016.](https://www.sec.gov/Archives/edgar/data/315293/000110465916101085/a16-5445_1ex4d2.htm)] [added: December 3, 2018.](https://www.sec.gov/Archives/edgar/data/315293/000119312518341158/d683184dex42.htm)] | | |

| | | | | | | [removed: 4.12*] [added: 4.11*] | | | [Amended and Restated Indenture, dated April 1, 2020, among Aon Corporation, Aon plc, Aon Global Limited, Aon Global Holdings plc and The Bank of New York Mellon Trust Company, N.A. (amending and restating the Indenture, dated December 3, 2018) - incorporated by reference to Exhibit 4.6 to Aon’s Current Report on Form 8-K12B filed April 1, 2020.](https://www.sec.gov/Archives/edgar/data/315293/000119312520093512/d867242dex46.htm) | | |

| | | | | | | 4.13* | | | [Form of [removed: 4.500%] [added: 3.750%] Senior Note due [removed: 2028 -] [added: 2029,] incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed [removed: December 3, 2018.](https://www.sec.gov/Archives/edgar/data/315293/000119312518341158/d683184dex42.htm)] [added: May 2, 2019.](https://www.sec.gov/Archives/edgar/data/315293/000119312519135074/d705892dex42.htm)] | | |

| | | | | | | 4.14* | | | [Form of [removed: 3.750%] [added: 2.800%] Senior Note due [removed: 2029,] [added: 2030 -] incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed May [removed: 2, 2019.](https://www.sec.gov/Archives/edgar/data/315293/000119312519135074/d705892dex42.htm)] [added: 15, 2020.](https://www.sec.gov/Archives/edgar/data/315293/000119312520144159/d929582dex42.htm)] | | |

| | | | | | | [removed: 4.15*] [added: 4.25*] | | | [Form of [removed: 2.800%] [added: 5.000%] Senior Note due [removed: 2030 -] [added: 2032 –] incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed [removed: May 15, 2020.](https://www.sec.gov/Archives/edgar/data/315293/000119312520144159/d929582dex42.htm)] [added: September 12, 2022.](https://www.sec.gov/Archives/edgar/data/315293/000119312522242984/d357255dex42.htm)] | | |

| | | | | | | [removed: 4.16] [added: 4.15] | | | [Description of Securities of Aon plc that are registered under Section 12 of the Securities Exchange Act of 1934, as [removed: amended.](https://www.sec.gov/Archives/edgar/data/315293/000162828025006093/exhibit4162024.htm)] [added: amended.](https://www.sec.gov/Archives/edgar/data/315293/000162828026008116/a415.htm)] | | |

| | | | | | | [removed: 4.17*] [added: 4.16*] | | | [First Indenture Supplement, dated August 23, 2021, among Aon Corporation, Aon Global Holdings plc, Aon Global Limited, Aon plc and The Bank of New York Mellon Trust Company, N.A., as trustee – incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed August 23, 2021.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312521254127/d202124dex42.htm) | | |

| | | | | | | [removed: 4.18*] [added: 4.17*] | | | [Form of 2.050% Senior Note due 2031 – incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed August 23, 2021.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312521254127/d202124dex42.htm) | | |

| | | | | | | [removed: 4.19*] [added: 4.18*] | | | [Form of 2.900% Senior Note due 2051 – incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed August 23, 2021.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312521254127/d202124dex42.htm) | | |

| | | | | | | [removed: 4.20*] [added: 4.19*] | | | [Second Indenture Supplement, dated December 2, 2021, among Aon Corporation, Aon Global Holdings plc, Aon Global Limited, Aon plc and The Bank of New York Mellon Trust Company, N.A., as trustee – incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed December 2, 2021.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312521346834/d249823dex42.htm) | | |

| | | | | | | [removed: 4.21*] [added: 4.20*] | | | [Form of 2.600% Senior Note due 2031 – incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed December 2, 2021.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312521346834/d249823dex42.htm) | | |

| | | | | | | [removed: 4.22*] [added: 4.21*] | | | [Third Indenture Supplement, dated February 28, 2022, among Aon Corporation, Aon Global Holdings plc, Aon Global Limited, Aon plc and The Bank of New York Mellon Trust Company, N.A., as trustee – incorporated by reference to Exhibit 4.2 to Aon’ Current Report on Form 8-K filed February 28, 2022.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312522058150/d944068dex42.htm) | | |

| | | | | | | [removed: 4.23*] [added: 4.22*] | | | [Form of 2.850% Senior Note due 2027 – incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed February 28, 2022.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312522058150/d944068dex42.htm) | | |

| | | | | | | [removed: 4.24*] [added: 4.23*] | | | [Form of 3.900% Senior Note due 2052 – incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8-K filed February 28, 2022.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312522058150/d944068dex42.htm) | | |

| | | | | | | [removed: 4.25*] [added: 4.24*] | | | [Fourth Indenture Supplement, dated September 12, 2022, among Aon Corporation, Aon Global Holdings plc, Aon Global Limited, Aon plc and The Bank of New York Mellon Trust Company, N.A., as trustee – incorporated by reference to Exhibit 4.2 to Aon’ Current Report on Form 8-K filed September 12, 2022.](https://www.sec.gov/Archives/edgar/data/315293/000119312522242984/d357255dex42.htm) | | |

| | | | | | | [removed: 4.26*] [added: 4.28*] | | | [Form of [removed: 5.000%] [added: 5.350%] Senior [removed: Note] [added: Notes] due [removed: 2032 –] [added: 2033 (included in Exhibit 4.2 to the Current Report on Form 8 K filed by Aon on February 28, 2023) —] incorporated by reference to Exhibit [removed: 4.2] [added: 4.3] to Aon’s Current Report on Form [removed: 8-K] [added: 8 K] filed [removed: September 12, 2022.](https://www.sec.gov/Archives/edgar/data/315293/000119312522242984/d357255dex42.htm)] [added: February 28, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523054079/d474704dex42.htm)] | | |

| | | | | | | [removed: 4.27*] [added: 4.26*] | | | [Amended and Restated Indenture, dated April 1, 2020, among Aon Corporation, Aon plc, AGL, AGH and the Trustee (amending and restating the Indenture, dated December 3, 2018, among Aon Corporation, AGL and the Trustee) (included in Exhibit 4.6 to the Current Report on Form 8 K12B filed by Aon on April 1, 2020) — incorporated by reference to Exhibit 4.1 to Aon’s Current Report on Form 8 K filed February 28, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312520093512/d867242dex46.htm) | | |

| | | | | | | [removed: 4.28*] [added: 4.27*] | | | [Fifth Indenture Supplement, dated as of February 28, 2023, among Aon Corporation, AGH, the Guarantors and the Trustee — incorporated by reference to Exhibit 4.2 to Aon’s Current Report on Form 8 K filed February 28, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523054079/d474704dex42.htm) | | |

| | | | | | | [removed: 4.29*] [added: 4.38*] | | | [Form of [removed: 5.350%] [added: 5.125%] Senior [removed: Notes] [added: Note] due [removed: 2033] [added: 2027] (included in Exhibit 4.2 to the Current Report on Form [removed: 8 K] [added: 8-K] filed by Aon on [removed: February 28, 2023) —] [added: March 1, 2024) -] incorporated by reference to Exhibit 4.3 to Aon’s Current Report on Form [removed: 8 K] [added: 8-K] filed [removed: February 28, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523054079/d474704dex42.htm)] [added: March 1, 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312524056156/d794687dex42.htm)] | | |

| | | | | | | [removed: 4.30*] [added: 4.29*] | | | [First Indenture Supplement, dated June 22, 2023, among Aon Corporation, Aon plc, Aon Global Limited, Aon Global Holdings plc, Aon North America, Inc. and The Bank of New York Mellon Trust Company, N.A. — incorporated by reference to Exhibit 4.14 to Aon’s Registration Statement on Form S 3 filed June 22, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523171894/d479772dex414.htm) | | |

| | | | | | | [removed: 4.31*] [added: 4.30*] | | | [First Indenture Supplement, dated June 22, 2023, among Aon Corporation, Aon plc, Aon Global Limited, Aon Global Holdings plc, Aon North America, Inc. and The Bank of New York Mellon Trust Company, N.A. — incorporated by reference to Exhibit 4.16 to Aon’s Registration Statement on Form S 3 filed June 22, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523171894/d479772dex416.htm) | | |

| | | | | | | [removed: 4.32*] [added: 4.31*] | | | [First Indenture Supplement, dated June 22, 2023, among Aon plc, Aon Corporation, Aon Global Limited, Aon Global Holdings plc, Aon North America, Inc. and The Bank of New York Mellon Trust Company, N.A. — incorporated by reference to Exhibit 4.18 to Aon’s Registration Statement on Form S 3 filed June 22, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523171894/d479772dex418.htm) | | |

| | | | | | | [removed: 4.33*] [added: 4.32*] | | | [First Indenture Supplement, dated June 22, 2023, among Aon plc, Aon Corporation, Aon Global Limited, Aon Global Holdings plc, Aon North America, Inc. and The Bank of New York Mellon Trust Company, N.A. — incorporated by reference to Exhibit 4.20 to Aon’s Registration Statement on Form S 3 filed June 22, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523171894/d479772dex420.htm) | | |

| | | | | | | [removed: 4.34*] [added: 4.33*] | | | [First Indenture Supplement, dated June 22, 2023, among Aon plc, Aon Corporation, Aon Global Limited, Aon Global Holdings plc, Aon North America, Inc. and The Bank of New York Mellon Trust Company, N.A. — incorporated by reference to Exhibit 4.22 to Aon’s Registration Statement on Form S 3 filed June 22, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523171894/d479772dex422.htm) | | |

| | | | | | | [removed: 4.35*] [added: 4.34*] | | | [Sixth Indenture Supplement, dated June 22, 2023, among Aon Corporation, Aon plc, Aon Global Limited, Aon Global Holdings plc, Aon North America, Inc. and The Bank of New York Mellon Trust Company, N.A. — incorporated by reference to Exhibit 4.29 to Aon’s Registration Statement on Form S 3 filed June 22, 2023.](https://www.sec.gov/Archives/edgar/data/315293/000119312523171894/d479772dex429.htm) | | |

| | | | | | | [removed: 4.36*] [added: 4.35*] | | | [Form of Aon Ordinary Share Certificate - incorporated by reference to Exhibit 4.1 to Aon’s Registration Statement on Form S-4 filed February 26, 2024.](https://www.sec.gov/Archives/edgar/data/315293/000119312524045397/d615553dex41.htm) | | |

| | | | | | | [removed: 4.37*] [added: 4.36*] | | | [Base Indenture, dated March 1, 2024, among Aon North America, Inc., the Co-Issuers and Guarantors party thereto, and the Bank of New York Mellon Trust Company, N.A. - incorporated by reference to Aon’s Current Report on Form 8-K filed March 1, 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312524056156/d794687dex41.htm) | | |

| | | | | | | [removed: 4.38*] [added: 4.37*] | | | [First Indenture Supplement, dated March 1, 2024, among Aon North America, Inc., the Co-Issuers and Guarantors party thereto, and the Bank of New York Mellon Trust Company, N.A. - incorporated by reference to Aon’s Current Report on Form 8-K filed March 1, 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312524056156/d794687dex42.htm) | | |

| | | | | | | 4.39* | | | [Form of [removed: 5.125%] [added: 5.150%] Senior Note due [removed: 2027] [added: 2029] (included in Exhibit 4.2 to the Current Report on Form 8-K filed by Aon on March 1, 2024) - incorporated by reference to Exhibit [removed: 4.3] [added: 4.4] to Aon’s Current Report on Form 8-K filed March 1, 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312524056156/d794687dex42.htm) | | |

| | | | | | | 4.40* | | | [Form of [removed: 5.150%] [added: 5.300%] Senior Note due [removed: 2029] [added: 2031] (included in Exhibit 4.2 to the Current Report on Form 8-K filed by Aon on March 1, 2024) - incorporated by reference to Exhibit [removed: 4.4] [added: 4.5] to Aon’s Current Report on Form 8-K filed March 1, 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312524056156/d794687dex42.htm) | | |

| | | | | | | 4.41* | | | [Form of [removed: 5.300%] [added: 5.450%] Senior Note due [removed: 2031] [added: 2034] (included in Exhibit 4.2 to the Current Report on Form 8-K filed by Aon on March 1, 2024) - incorporated by reference to Exhibit [removed: 4.5] [added: 4.6] to Aon’s Current Report on Form 8-K filed March 1, 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312524056156/d794687dex42.htm) | | |

| | | | | | | 4.42* | | | [Form of [removed: 5.450%] [added: 5.750%] Senior Note due [removed: 2034] [added: 2054] (included in Exhibit 4.2 to the Current Report on Form 8-K filed by Aon on March 1, 2024) - incorporated by reference to Exhibit [removed: 4.6] [added: 4.7] to Aon’s Current Report on Form 8-K filed March 1, 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312524056156/d794687dex42.htm) | | |

| | | | | | | 10.1* | | | [$1,000,000,000 Credit Agreement, dated September 28, 2021, among Aon plc, Aon Corporation, Aon UK Limited, Aon Global Holdings plc and Aon Global Limited with Citibank, N.A., as administrative agent, the lenders party thereto, HSBC Bank USA, National Association and Morgan Stanley Senior Funding, Inc., as syndication agents, and Citibank, N.A., HSBC Securities (USA) and Morgan Stanley Senior Funding, Inc., as joint lead arrangers and joint [removed: bookrunners incorporated] [added: bookrunners](https://www.sec.gov/Archives/edgar/data/0000315293/000119312521287444/d222574dex101.htm) [incorporated] by reference to Exhibit 10.1 to Aon’s Current Report on Form 8 K filed on September 30, 2021.](https://www.sec.gov/Archives/edgar/data/0000315293/000119312521287444/d222574dex101.htm) | | |

| | | | | | | 10.2* | | | [removed: [Term Loan] [added: [Amendment No. 1 to the] Credit Agreement, dated February 16, 2024, among Aon [removed: North America, Inc., Aon] plc, Aon Corporation, Aon Global Holdings plc, Aon Global [removed: Limited,] [added: Limited and Aon North America, Inc.,] Citibank, N.A., as administrative agent, [removed: HSBC Securities (USA) Inc., JPMorgan Chase Bank, N.A.,] and [removed: Morgan Stanley Senior Funding, Inc. as syndication agents, and] the lenders party thereto — incorporated by reference to Aon's Annual Report on Form 10-K filed February 16, [removed: 2024.](https://www.sec.gov/Archives/edgar/data/315293/000162828024005392/exhibit1022023.htm)] [added: 2024.](https://www.sec.gov/Archives/edgar/data/315293/000162828024005392/exhibit103-amendmentnoic.htm)] | | |

| | | | | | | 10.3* | | | [Amendment No. [removed: 1] [added: 2] to the [removed: Term Loan] Credit Agreement, dated April 16, 2024, among Aon [removed: North America, Inc., Aon] plc, Aon Corporation, Aon Global Holdings plc, Aon Global [removed: Limited,] [added: Limited and Aon North America, Inc.,] Citibank, N.A., as administrative agent, [removed: HSBC Securities (USA) Inc., JPMorgan Chase Bank, N.A.,] and [removed: Morgan Stanley Senior Funding, Inc. as syndication agents, and] the lenders party thereto — incorporated by reference to [removed: Aon's] [added: Aon’s] Current Report on Form 8-K filed April 19, [removed: 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000095015724000633/ex10-1.htm)] [added: 2024.](https://www.sec.gov/Archives/edgar/data/0000315293/000095015724000633/ex10-2.htm)] | | |

| | | | | | | 10.22*# | | | [Aon plc 2011 Incentive Plan (as amended and restated effective April 18, 2025) - incorporated by reference to Exhibit 10.2 to Aon’s Current Report on Form 8-K filed July 3, 2025.](https://www.sec.gov/Archives/edgar/data/315293/000162828023026117/exhibit1032023.htm) | | |

| | | | | | | 10.34*# | | | [Performance Share Unit Agreement, dated December 31, 2025, by and between Aon plc and Gregory C. Case](https://www.sec.gov/Archives/edgar/data/315293/000162828023026117/exhibit1082023.htm) [- incorporated by reference to Exhibit 10.2 to Aon’s Current Report on Form 8-K filed January 2, 2026.](https://www.sec.gov/Archives/edgar/data/315293/000162828023026117/exhibit1082023.htm) | | |

| | | | | | | 10.60# | | | [Employment Agreement, dated January 2, 2026, between Aon Corporation and Andy Marcell.](https://www.sec.gov/Archives/edgar/data/315293/000162828026008116/a1060.htm) | | |

| | | | | | | 10.70# | | | [Eighth Amendment to the Amended and Restated Aon Deferred Compensation Plan, effective July 31,2025.](https://www.sec.gov/Archives/edgar/data/315293/000162828026008116/exhibit1070eighthamendment.htm) | | |

| | | | | | | 10.82# | | | [Ninth Amendment to the Aon Supplemental Savings Plan, effective July 31, 2025.](https://www.sec.gov/Archives/edgar/data/315293/000162828026008116/exhibit1082ninthamendment-.htm) | | |

| Consent of Independent Registered Public Accounting Firm | | | | | | | | | | | |

| | | | | | | 23 | | | [Consent of Independent Registered Public Accounting Firm](https://www.sec.gov/Archives/edgar/data/315293/000162828026008116/exhibit23.htm) | | |

| | | | | | | | | | | | |

| | | | | | | | | | | | |