Aon plc: 10-K Risk Factor Changes

The following is a summary of the principal risks associated with our businesses and the industries in which we operate generally as described in more detail in this report. We encourage you to carefully review the full risk factors immediately following this summary as well as the other information in this report.

•An overall decline in economic and business activity could have a material adverse effect on the financial condition and results of operations of our business. •We face significant competitive pressures from traditional and non-traditional competitors that could affect our business. •If we are unable to effectively develop and implement innovative strategies, efficiencies and new solutions for our clients, our reputation, ability to compete effectively and financial condition may be adversely affected. •If our clients are not satisfied with our services, we may face additional cost, loss of profit opportunities, damage to our reputation, or legal liability. •Revenues from commission arrangements may fluctuate due to many factors, including cyclical or permanent changes in the insurance and reinsurance markets outside of our control. •The profitability of our operations may not meet our expectations due to unexpected costs, cost overruns, inflation, early contract terminations, unrealized assumptions used in our contract bidding process or the inability to maintain our prices.

•We are exposed to fluctuations in currency exchange rates that could negatively impact our financial results and cash flows. Similarly, changes in interest rates and deterioration of credit quality could reduce the value of our cash balances and investment portfolios and adversely affect our financial condition or results. •We have debt outstanding that could adversely affect our financial flexibility. In addition, a decline in the credit ratings of our senior debt and commercial paper may adversely affect our borrowing costs, access to capital, and financial flexibility. •Our tax assets and liabilities are subject to a variety of different factors, including the adoption and implementation of OECD tax proposals, which could create volatility in our global effective tax rate, expose us to greater than anticipated tax liabilities or cause us to adjust previously recognized tax assets and liabilities. 10 10 10 10 10 10 •We are a holding company and, therefore, may not be able to receive dividends or other payments in needed amounts from our subsidiaries.

•We are subject to E&O claims against us as well as other contingencies and legal proceedings, some of which, if determined unfavorably to us, could have a material adverse effect on our financial condition or results of operations. •Our businesses are subject to extensive governmental regulation, which could reduce our profitability, limit our growth, or subject us to legal and regulatory actions. •Failure to protect our intellectual property rights, or allegations that we have infringed on the intellectual property rights of others, could harm our reputation, ability to compete effectively, and financial condition.

•Our results of operations have been adversely affected and could be materially adversely affected in the future by the effects of natural or man-made disasters, including health pandemics or the impacts of climate change. •Our success depends on our ability to retain, attract and develop experienced and qualified personnel, including our senior management team and other professional personnel. •We may not recognize all of the expected benefits from our Accelerating Aon United program and other operation improvement initiatives.

•We rely on complex information technology systems and networks to operate our business. Any significant system or network disruption due to a breach in the security of our information technology systems could have a negative impact on our reputation, operations, sales, and operating results. •Improper disclosure of confidential, personal, or proprietary data could result in regulatory scrutiny, legal liability, or harm to our reputation.

•The Transaction is subject to customary closing conditions, including conditions related to regulatory approvals, and may not be completed on a timely basis, or at all, or may be completed on a basis that has a material impact on the value of the combined company. Failure to close the Transaction could negatively impact our share price and future business and financial results. •While the Transaction is pending, we are subject to business uncertainties related to our relationships with employees, clients and suppliers, which could adversely affect our business and operations. These uncertainties could also adversely affect the combined company following the Transaction.

•We are incorporated in Ireland, and Irish law differs from the laws in effect in the U.S. and may afford less protection to holders of our securities. •As an Irish public limited company, certain capital structure decisions regarding the Company will require the approval of shareholders, which may limit the Company’s flexibility to manage its capital structure. •The implementation of the OECD global minimum tax regime in Ireland could have a material adverse effect on our global effective tax rate, results of operations, cash flows and financial condition.

In 2023, we initiated a three-year restructuring program, Accelerating Aon United Program (the “Program”). The Program is intended to streamline our technology infrastructure, optimize our leadership structure and resource alignment, and reduce 20 20 20 20 20 20 our real estate footprint to align to our hybrid working strategy. The Program will include technology-related costs to facilitate streamlining and simplifying operations, headcount reduction costs, and costs associated with asset impairments, including real estate consolidation costs. The Program is currently expected to result in cumulative costs of approximately $1,000 million, consisting of approximately $900 million of cash charges and approximately $100 million of non-cash charges. We estimate that our annualized savings from the Program will be approximately $350 million by the end of 2026. Actual total costs, savings and timing may vary from these estimates due to changes in the scope or assumptions underlying the Program and other operational improvement initiatives. We therefore cannot assure that we will achieve the targeted savings. Unanticipated costs or unrealized savings in connection with the Program and other operational improvement initiatives could adversely affect our consolidated financial statements.

The completion of the Transaction is subject to the satisfaction or waiver of a number of conditions as set forth in the Merger Agreement, including, among others, the expiration or termination of the applicable waiting periods under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”), the approval of regulatory authorities in the United Kingdom and Ireland, the effectiveness of a Registration Statement and the approval for listing on NYSE of the ordinary shares of Aon to be issued in connection with the Transaction. There can be no assurance that the expiration or termination of the applicable waiting periods under the HSR Act or the other conditions to the obligations of the parties to effect the Transaction will be satisfied or waived. In particular, foreign, federal, state or local governmental or regulatory authorities and, in certain instances, private parties may seek to challenge the Transaction and/or impose conditions on Aon or NFP as a condition to completion of the Transaction under applicable antitrust or other laws. In addition, there can be no assurance that any consents, clearances or approvals necessary or advisable to be obtained in connection with the Transaction will be obtained in a timely manner or at all, or whether they will be subject to actions, conditions, limitations or restrictions that may jeopardize or delay the completion of the Transaction, materially reduce or delay the anticipated benefits of the Transaction or allow the parties to terminate the Merger Agreement. Pursuant to the terms of the Merger Agreement, Aon may be required to offer and agree to undertake certain specified behavioral remedies with regulatory authorities. If Aon is required to divest assets or businesses related to NFP, there can be no assurance that it will be able to negotiate such divestitures expeditiously or on favorable terms or that the governmental authorities will approve the terms of such divestitures. If the Transaction, or the integration of the companies’ respective businesses, is not completed within the expected time frame, such delay may materially and adversely affect the synergies and other benefits that Aon expects to achieve as a result of the Transaction and could result in additional costs or liabilities, loss of revenue and other adverse effects on Aon’s business, financial condition and results of operations.

If the Transaction is not completed for any reason, Aon’s ongoing business may be adversely affected and, without realizing any of the potential benefits of completing the Transaction, Aon will be subject to a number of risks, including the following: •Aon will be required to pay certain costs and expenses relating to the Transaction; •if the Merger Agreement is terminated under specified circumstances or circumstances related to a failure to obtain the required antitrust clearances or other regulatory clearances provided for by the Merger Agreement, Aon may be obligated to pay to NFP a termination fee equal to $250 million; •Aon may experience negative reactions from the financial markets, including negative impacts on the market price of Aon’s securities; •the manner in which clients, vendors, business partners and other third parties perceive Aon may be negatively impacted, which in turn could affect its ability to compete for new business or to obtain renewals in the marketplace; •matters relating to the Transaction (including integration planning) may require substantial commitments of time and resources by management, which could otherwise have been devoted to other opportunities that may have been beneficial to Aon; and •Aon could be subject to litigation related to any failure to close the Transaction or related to any enforcement proceeding commenced against it to perform its obligations under the Merger Agreement. If the Transaction does not close, these risks may materialize and may adversely affect Aon’s business, financial results and market price.

During the pendency of the Transaction, it is possible that customers, suppliers, commercial partners and/or other persons with whom Aon or NFP has a business relationship may elect to delay or defer certain business decisions or decide to seek to 25 25 25 25 25 25 terminate, change or renegotiate their relationships with Aon or NFP, as the case may be, as a result of the Transaction, which could significantly reduce the expected benefits of the Transaction and/or negatively affect Aon’s or NFP’s revenues, earnings and cash flows, NFP’s future plans and the market price of Aon ordinary shares, regardless of whether the Transaction is completed. Matters relating to the Transaction (including integration planning) will require substantial commitments of time and resources by Aon management, which would otherwise have been devoted to day-to-day operations and other opportunities that may have been beneficial to Aon. Aon will also incur significant costs related to the Transaction, some of which must be paid even if the Transaction is not completed. These costs are substantial and include financial advisory, legal and accounting costs. Each of the risks described above may be exacerbated by delays or other adverse developments with respect to the completion of the Transaction.

Uncertainty about the effects of the Transaction on employees may impair the ability to attract, retain and motivate key personnel during the pendency of the Transaction and, if the Transaction is completed, for a period of time thereafter. If key employees depart because of issues related to the uncertainty and difficulty of integration or a desire not to remain with Aon following the completion of the Transaction, Aon may have to incur significant costs in identifying, hiring and retaining replacements for departing employees and may lose significant expertise and talent.

Aon expects to fund the cash consideration payable in the Transaction and the repayment or refinancing of NFP’s existing debt arrangements contemplated by the Merger Agreement, through debt financing. Aon’s ability to obtain debt financing, and the pricing and terms thereof, will be subject to various factors, including market conditions, operating performance and Aon’s ability to incur additional debt. The receipt of financing by Aon is not a condition to completion of the Transaction and, accordingly, Aon will be required to complete the Transaction (assuming that all of the conditions to its obligations under the Merger Agreement are satisfied) whether or not debt financing is available at all or on acceptable terms.

Aon and NFP entered into the Merger Agreement with the expectation that the Transaction would result in various benefits, including, among other things, operating efficiencies, synergies and cost savings. Achieving the anticipated benefits of the Transaction is subject to a number of uncertainties, including whether the businesses of Aon and NFP can be integrated in an efficient and effective manner. 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 of NFP into the Aon organization could also result in the disruption of ongoing businesses, processes, systems and business relationships or inconsistencies in standards, controls, procedures, practices, policies and compensation arrangements, any of which could adversely affect Aon’s ability to achieve the anticipated benefits of the Transaction. The integration process is subject to a number of risks and uncertainties, and no assurance can be given that the anticipated benefits of the Transaction 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.

Aon expects to incur a number of non-recurring costs associated with the Transaction, combining the organizations and achieving anticipated synergies. These costs will be significant and additional unanticipated costs may also be incurred in connection with the Transaction and combination of the organizations. 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 the Company to offset integration-related costs over time, this net benefit may not be achieved in the near term or at all.

No assurances can be given as to what Aon’s global effective tax rate will be after the closing of the Transaction because of, among other things, uncertainty regarding the global mix of income following closing, uncertainty regarding the ability, 26 26 26 26 26 26 costs and time necessary to integrate NFP’s business operations and entities, uncertainty regarding complex tax rules in NFP’s largest jurisdiction (the U.S.) and the application of those rules to Aon following closing, and uncertainty with respect to Ireland’s Pillar Two tax regime which will apply to the combined income and taxes of Aon and NFP following closing. As a result, Aon’s actual global effective tax rate may vary from expectations following the Transaction and that variance may be material.