Aon plc

“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, has and could adversely affect these businesses as a significant portion of our revenue is determined as a percentage of premiums charged to our clients.”

Annual report 2025A · The company itself

“Uncertainty regarding, or any changes to, state or federal law, or the interpretation of such law by applicable regulatory agencies could delay client adoption of our health care exchange, impair our ability to retain clients who have adopted our health care exchange, or cause insurance carriers to alter or eliminate the products and plans that they offer or attempt to move members into new products or plans for which we receive lower commissions.”

Annual report 2025A · The company itself

“Insurance intermediaries have traditionally been remunerated by base commissions paid by insurance carriers in respect of insurance placements for clients, or by fees paid by clients. Intermediaries also obtain other revenue from insurance carriers.”

Annual report 2025A · The company itself

“A significant portion of our revenue consists of commissions paid to us out of the premiums that insurers and reinsurers charge our clients for coverage. We have no control over premium rates, and our revenues and profitability are subject to change to the extent that premium rates fluctuate or trend in a particular direction.”

Annual report 2025A · The company itself

“In insurance brokerage, our dedicated teams of risk professionals utilize comprehensive analytics to design strategically resilient insurance programs and provide our clients access to Aon’s proprietary facilities, such as Aon Client Treaty and all other forms of capital, regardless of insurance carrier, placement structure or geography.”

Annual report 2025A · The company itself

“Reinsurance Solutions includes treaty reinsurance, facultative reinsurance, Strategy and Technology Group and capital markets. Treaty reinsurance addresses underwriting and capital objectives on a portfolio level, allowing our clients to more effectively manage the combination of premium growth, return on capital, and rating agency interests on an integrated basis.”

Annual report 2025A · The company itself

“Revenue and Compensation Our business generates revenues primarily through commissions, compensation from insurance and reinsurance companies for services we provide to them, and fees from customers.”

Annual report 2025A · The company itself

“We assist our clients with various matters, including advising on and placing insurance and reinsurance coverage and handling related claims, consulting on various human resources matters, and providing actuarial, investment consulting, asset management, and other services.”

Annual report 2025A · The company itself

“Revenue from Contracts with Customers Disaggregation of Revenue The following table summarizes revenue from contracts with customers by principal service line (in millions): Commercial Risk Solutions $ 8,497 $ 7,861 $ 7,043 Reinsurance Solutions 2,793 2,656 2,481 Total Risk Capital (1) 11,290 10,517 9,524 Health Solutions 3,839 3,335 2,433 Wealth Solutions 2,068 1,874 1,431 Total Human Capital (1) 5,907 5,209 3,864 Eliminations (16) (28) (12) Total revenue $ 17,181 $ 15,698 $ 13,376 (1)Includes inter-segment revenue.”

Annual report 2025A · The company itself

“As of December 31, 2025, we employed approximately 60,000 employees and conducted our operations in more than 120 countries.”

Annual report 2025A · The company itself

“Our cost efficiencies may also be impacted by factors such as our ability to transition consultants from completed projects to new assignments, to secure new business, to forecast demand for our services (and, consequently, appropriately manage the size and location of our workforce), to develop, attract and retain suitable capabilities and talent, to obtain third party services at favorable prices, and to manage key suppliers to maximize delivery; product and efficiency opportunities; inflation (including wage inflation); and the need to devote time and resources to training and professional and business development.”

Annual report 2025A · The company itself

“The global nature of our operations increases the complexity and cost of compliance with laws and regulations adding to our cost of doing business.”

Annual report 2025A · The company itself

“Pensions We sponsor defined benefit pension plans throughout the world. Our most significant plans are located in the U.S., the U.K., the Netherlands, and Canada, which are closed to new entrants.”

Annual report 2025A · The company itself

“Our profit margin, and therefore our profitability, is largely a function of the revenue generated from our services and the staffing costs for our personnel and related expenses. Accordingly, if we are not able to maintain the rates we charge for our services or appropriately manage the staffing costs of our personnel and related expenses, we may not be able to sustain our profit margin and our profitability will suffer.”

Annual report 2025A · The company itself

“Compensation and Benefits Compensation and benefits increased $702 million, or 8%, in 2025 compared to 2024. The increase was primarily driven by the inclusion of operating expenses from NFP and an increase in expenses associated with 6% organic revenue growth, partially offset by savings from Accelerating Aon United restructuring actions.”

Annual report 2025A · The company itself

“Accelerating Aon United Program Expenses In the third quarter of 2023, we initiated a three-year restructuring program called Accelerating Aon United Program (the “Program” or the “AAU Program”) with the purpose of streamlining our technology infrastructure, optimizing our leadership structure and resource alignment, and reducing the real estate footprint to align to our hybrid working strategy. The Program includes technology-related costs to facilitate streamlining and simplifying operations, headcount reduction costs, and costs associated with asset impairments, including real estate consolidation and technology costs.”

Annual report 2025A · The company itself

“Accelerating Aon United Program In the third quarter of 2023, Aon initiated a three-year restructuring program called the Accelerating Aon United Program (the “Program” or the “AAU Program”) with the purpose of streamlining the Company’s technology infrastructure, optimizing its leadership structure and resource alignment, and reducing the real estate footprint to align to its hybrid working strategy. The Program includes technology-related costs to facilitate streamlining and simplifying operations, headcount reduction costs, and costs associated with asset impairments, including real estate consolidation and technology costs. The Program is an investment in our 3x3 Plan that brings the best of the firm through our Aon United strategy, delivered as Risk Capital and Human Capital, and our Aon Client Leadership model, powered by Aon Business Services.”

Annual report 2025A · The company itself

“Our talent team delivers data, analytics, and advice to business leaders so they can make better workforce decisions and align their business and people strategies. We support clients across the full employee lifecycle, including talent assessment and selection, compensation benchmarking, total rewards strategy optimization, Corporate Governance and strategic employee communications.”

Annual report 2025A · The company itself

“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.”

Annual report 2025A · The company itself

“A downgrade in the credit ratings of our senior debt and commercial paper could increase our borrowing costs, reduce or eliminate our access to capital, reduce our financial flexibility, and limit our ability to implement our corporate strategy.”

Annual report 2025A · The company itself

“Interest income was $19 million in 2025, a decrease of $48 million, or 72%, from 2024, primarily reflecting interest earned on the investment of $5 billion of term debt proceeds in 2024, which were ultimately used to fund the acquisition of NFP. Interest Expense Interest expense, which represents the cost of our debt obligations and net interest expense on operating cash balances and other income-producing investments, was $815 million in 2025, an increase of $27 million, or 3%, from 2024.”

Annual report 2025A · The company itself

“Impact of Changing Economic Assumptions Changes in the discount rate and expected return on assets can have a material impact on pension obligations and pension expense. Holding all other assumptions constant, the following table reflects what a 25 BPS increase and decrease in our discount rate would have on our PBO at December 31, 2025 (in millions): Increase (decrease) in projected benefit obligation (1) 25 BPS Change in Discount Rate Increase Decrease U.K. plans $ (79) $ 83 U.S. plans $ (46) $ 48 Other plans $ (42) $ 44 (1)Increases to the PBO reflect increases to our pension obligations, while decreases in the PBO are recoveries toward fully-funded status. A change in the discount rate has an inverse relationship to the PBO.”

Annual report 2025A · The company itself

“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, 2025.”

Annual report 2025A · The company itself

“Wealth Solutions includes retirement consulting, pension administration, and investments consulting. Retirement consulting provides clients strategic design advice, actuarial services, risk management solutions including pension risk transfer, and integrated pension administration.”

Annual report 2025A · The company itself

“Aon has from time-to-time experienced and may experience in the future problems with the information technology systems of vendors, including breakdowns or other disruptions in communication services provided by a vendor, failure of a vendor to handle current or higher volumes, difficulties in the migration of services or data to third parties or the cloud hosted by third parties, cyber-attacks, and security breaches, any of which could adversely affect our ability to deliver products and services to customers and otherwise conduct business.”

Annual report 2025A · The company itself

“We rely on third parties, and in some cases subcontractors, to provide services, data, and information such as technology, information security, funds transfers, data processing, support functions, and administration that are critical to the operations of our business.”

Annual report 2025A · The company itself

“Information Technology Information technology, which represents costs associated with supporting and maintaining our infrastructure, increased $29 million, or 5%, in 2025 compared to 2024. The increase was primarily due to the inclusion of ongoing operating expenses from NFP and an increase in expenses associated with 6% organic revenue growth, partially offset by savings from Accelerating Aon United restructuring actions.”

Annual report 2025A · The company itself

“Purchase obligations are defined as agreements to purchase goods and services that are enforceable and legally binding on us, and that specify all significant terms, including the goods to be purchased or services to be rendered, the price at which the goods or services are to be rendered, and the timing of the transactions. Most of our purchase obligations are related to purchases of information technology services or other service contracts.”

Annual report 2025A · The company itself

“Accelerating Aon United Program Expenses In the third quarter of 2023, we initiated a three-year restructuring program called Accelerating Aon United Program (the “Program” or the “AAU Program”) with the purpose of streamlining our technology infrastructure, optimizing our leadership structure and resource alignment, and reducing the real estate footprint to align to our hybrid working strategy. The Program includes technology-related costs to facilitate streamlining and simplifying operations, headcount reduction costs, and costs associated with asset impairments, including real estate consolidation and technology costs.”

Annual report 2025A · The company itself

“Accelerating Aon United Program In the third quarter of 2023, Aon initiated a three-year restructuring program called the Accelerating Aon United Program (the “Program” or the “AAU Program”) with the purpose of streamlining the Company’s technology infrastructure, optimizing its leadership structure and resource alignment, and reducing the real estate footprint to align to its hybrid working strategy. The Program includes technology-related costs to facilitate streamlining and simplifying operations, headcount reduction costs, and costs associated with asset impairments, including real estate consolidation and technology costs.”

Annual report 2025A · The company itself

“Risks Related to Our Business •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.”

Annual report 2025A · The company itself

“The demand for property and casualty insurance generally rises as the overall level of economic activity increases and generally falls as such activity decreases, affecting both the commissions and fees generated by our Risk Capital segment. The economic activity that impacts property and casualty insurance is most closely correlated with employment levels, corporate revenues, and asset values.”

Annual report 2025A · The company itself

“This diversification of our client base helps provide our firm with stability in different economic scenarios that could affect specific industries, customer segments, or geographies.”

Annual report 2025A · The company itself

“Share Repurchase Program We have a share repurchase program authorized by our Board of Directors. The Repurchase Program was established in April 2012 with $5.0 billion in authorized repurchases, and was increased by $5.0 billion in authorized repurchases in each of November 2014, June 2017, and November 2020, and by $7.5 billion in February 2022 for a total of $27.5 billion in repurchase authorizations. The following table summarizes our share repurchase activity (in millions, except per share data): Shares repurchased 2.7 3.1 Average price per share $ 365.91 $ 325.56 Repurchase costs recorded to accumulated deficit $ 1,000 $ 1,000 At December 31, 2025, the remaining authorized amount for share repurchase under the Repurchase Program was approximately $1.3 billion.”

Annual report 2025A · The company itself

“Capital markets is a global investment bank with expertise in insurance-linked securities, capital raising, strategic advice, restructuring, and mergers and acquisitions. We partner with insurers, reinsurers, investment firms, and corporations in executing innovative risk management products, capital market solutions, and corporate finance advisory services.”

Annual report 2025A · The company itself

“Wealth Solutions includes retirement consulting, pension administration, and investments consulting. Retirement consulting provides clients strategic design advice, actuarial services, risk management solutions including pension risk transfer, and integrated pension administration.”

Annual report 2025A · The company itself

“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 plans and defined contribution plans. With respect to defined contributions, we offer Master Trusts and Pooled Employer Plans. Our delegated investment solutions provide ongoing management of investment programs in both partial or full discretionary models.”

Annual report 2025A · The company itself

“Furthermore, our investment businesses provide advice to clients on: investment strategy, which can include advice on setting investment objectives, asset allocation, and hedging strategies; selection (or removal) of investment managers; the investment in different investment instruments and products; and the selection of other investment service providers such as custodians and transition managers. For some clients, we are responsible for making decisions on these matters and we may implement such decisions in a fiduciary or agency capacity without assuming title over the underlying funds or assets invested.”

Annual report 2025A · The company itself

“Reinsurance Solutions revenue increased $137 million, or 5%, to $2.8 billion in 2025, compared to $2.7 billion in 2024. Organic revenue growth was 6% in 2025, reflecting growth in treaty, driven by net new business and strong retention, strength in facultative placements, and double-digit growth in insurance-linked securities.”

Annual report 2025A · The company itself

“Wealth Solutions revenue increased $194 million, or 10%, to $2.1 billion in 2025, compared to $1.9 billion in 2024. 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. Growth in Retirement was driven by continued strong demand for advisory work in the UK and EMEA related to the ongoing impact of regulatory change.”

Annual report 2025A · The company itself

“We assist our clients with various matters, including advising on and placing insurance and reinsurance coverage and handling related claims, consulting on various human resources matters, and providing actuarial, investment consulting, asset management, and other services.”

Annual report 2025A · The company itself

“Human Capital Health Solutions revenue increased $504 million, or 15%, to $3.8 billion in 2025, compared to $3.3 billion in 2024. Organic revenue growth was 5% in 2025, reflecting strong growth globally in core health and benefits brokerage, driven by net new business and ongoing strong retention.”

Annual report 2025A · The company itself

“Revenue from Contracts with Customers Disaggregation of Revenue The following table summarizes revenue from contracts with customers by principal service line (in millions): Commercial Risk Solutions $ 8,497 $ 7,861 $ 7,043 Reinsurance Solutions 2,793 2,656 2,481 Total Risk Capital (1) 11,290 10,517 9,524 Health Solutions 3,839 3,335 2,433 Wealth Solutions 2,068 1,874 1,431 Total Human Capital (1) 5,907 5,209 3,864 Eliminations (16) (28) (12) Total revenue $ 17,181 $ 15,698 $ 13,376 (1)Includes inter-segment revenue.”

Annual report 2025A · The company itself

“Human Capital Health Solutions includes consulting and brokerage, consumer benefits, compensation, and talent advisory services. Consulting and brokerage develops and implements innovative, customized health and benefits strategies for our clients to manage risk, drive engagement, and strengthen their workforce through improved health and wellbeing.”

Annual report 2025A · The company itself

“In particular, our health care exchange business depends upon the private sector of the U.S. insurance system and its role in financing health care delivery, and insurance carriers’ use and payment of commissions to agents, brokers, and other organizations to market and sell individual and family health insurance products and plans.”

Annual report 2025A · The company itself

“In pursuing our corporate strategy, we often acquire other businesses or dispose of or exit businesses we currently own and we routinely are actively engaged in the process of identifying, analyzing, and negotiating possible transactions. The success of this strategy is dependent upon our ability to identify appropriate acquisition and disposition targets, negotiate transactions on favorable terms, secure regulatory approval of transactions where required, complete transactions and, in the case of acquisitions, successfully integrate them into our existing businesses and culture.”

Annual report 2025A · The company itself

“If acquisitions are made, there can be no assurance that we will realize the anticipated benefits of such acquisitions, including, but not limited to, revenue growth, operational efficiencies, or expected synergies, and we could incur unexpected or significant costs in connection with integration. Furthermore, integration of acquisitions, including the NFP acquisition, could divert management’s attention from other business concerns and involve inconsistencies in standards, controls, procedures, practices, policies and compensation arrangements, any of which could adversely affect our ability to achieve the anticipated benefits of a given acquisition or otherwise negatively impact our business.”

Annual report 2025A · The company itself

“If we are not able to manage the growing complexity of these businesses, including improving, refining, or revising our systems and operational practices, and enlarging the scale and scope of the businesses, our business may be adversely affected. Other risks include developing knowledge of and experience in the new business, product or service, integrating the acquired business into our systems and culture, recruiting and retaining experienced professionals, and developing and capitalizing on new relationships with experienced market participants. External factors, such as compliance with new or revised regulations, competitive alternatives, and shifting market preferences may also impact the successful implementation of a new line of business, products, or services. Failure to manage these risks in the acquisition or development of new businesses could materially and adversely affect our business, results of operations, and financial condition.”

Annual report 2025A · The company itself

“Acquisitions and Dispositions of Businesses Completed Acquisitions 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.”

Annual report 2025A · The company itself

“Our profitability is highly dependent upon our ability to control our costs and improve our efficiency. 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, changing workforce, effectively control our costs, or improve our efficiency.”

Annual report 2025A · The company itself

“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 our real estate footprint to align to our hybrid working strategy.”

Annual report 2025A · The company itself

“Accelerating Aon United Program In the third quarter of 2023, Aon initiated a three-year restructuring program called the Accelerating Aon United Program (the “Program” or the “AAU Program”) with the purpose of streamlining the Company’s technology infrastructure, optimizing its leadership structure and resource alignment, and reducing the real estate footprint to align to its hybrid working strategy. The Program includes technology-related costs to facilitate streamlining and simplifying operations, headcount reduction costs, and costs associated with asset impairments, including real estate consolidation and technology costs. The Program is an investment in our 3x3 Plan that brings the best of the firm through our Aon United strategy, delivered as Risk Capital and Human Capital, and our Aon Client Leadership model, powered by Aon Business Services.”

Annual report 2025A · The company itself

“Our profitability is highly dependent upon our ability to control our costs and improve our efficiency. 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, changing workforce, effectively control our costs, or improve our efficiency.”

Annual report 2025A · The company itself

“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 our real estate footprint to align to our hybrid working strategy.”

Annual report 2025A · The company itself

“Accelerating Aon United Program In the third quarter of 2023, Aon initiated a three-year restructuring program called the Accelerating Aon United Program (the “Program” or the “AAU Program”) with the purpose of streamlining the Company’s technology infrastructure, optimizing its leadership structure and resource alignment, and reducing the real estate footprint to align to its hybrid working strategy. The Program includes technology-related costs to facilitate streamlining and simplifying operations, headcount reduction costs, and costs associated with asset impairments, including real estate consolidation and technology costs. The Program is an investment in our 3x3 Plan that brings the best of the firm through our Aon United strategy, delivered as Risk Capital and Human Capital, and our Aon Client Leadership model, powered by Aon Business Services.”

Annual report 2025A · The company itself

“Our businesses are subject to extensive legal and regulatory oversight throughout the world, including the Irish Companies Act, the U.S. securities laws, rules, and regulations, the rules and regulations promulgated by the FCA and a variety of other laws, rules, and regulations addressing, among other things, licensing, data privacy, data management and data protection, artificial intelligence, trade sanctions laws, restrictions and export controls, anti-money laundering, wage-and-hour standards, employment and labor relations, antitrust and competition, anti-corruption, currency, reserves, government contracting, and the amount of local investment with respect to our operations in certain countries.”

Annual report 2025A · The company itself

“Changes in laws and regulations could mandate significant and costly changes to the way we implement our services and solutions, impose additional licensure requirements or costs to our operations, workforce and services, or cause us to cease offering certain services or solutions.”

Annual report 2025A · The company itself

“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.”

Annual report 2025A · The company itself

“Our business’ regulatory oversight also includes licensing of insurance brokers and agents, managing general agency or general underwriting operations, and the regulation of the handling and investment of client funds held in a fiduciary capacity.”

Annual report 2025A · The company itself

“In addition, depending on the circumstances, the acquisition, ownership and/or disposition of our ordinary shares may subject shareholders to different or additional tax consequences under Irish law including, but not limited to, Irish stamp duty, dividend withholding tax and capital acquisitions tax. As an Irish public limited company, certain capital structure decisions regarding the Company require the approval of shareholders, which may limit the Company’s flexibility to manage its capital structure.”

Annual report 2025A · The company itself

“Reinsurance Solutions revenue increased $137 million, or 5%, to $2.8 billion in 2025, compared to $2.7 billion in 2024. Organic revenue growth was 6% in 2025, reflecting growth in treaty, driven by net new business and strong retention, strength in facultative placements, and double-digit growth in insurance-linked securities.”

Annual report 2025A · The company itself

“Our businesses are subject to extensive legal and regulatory oversight throughout the world, including the Irish Companies Act, the U.S. securities laws, rules, and regulations, the rules and regulations promulgated by the FCA and a variety of other laws, rules, and regulations addressing, among other things, licensing, data privacy, data management and data protection, artificial intelligence, trade sanctions laws, restrictions and export controls, anti-money laundering, wage-and-hour standards, employment and labor relations, antitrust and competition, anti-corruption, currency, reserves, government contracting, and the amount of local investment with respect to our operations in certain countries.”

Annual report 2025A · The company itself

“In addition, changes in laws, government regulations, or the way those regulations are interpreted in the jurisdictions in which we operate could affect the viability, value, use, or delivery of benefits and human resources programs, including changes in regulations relating to health and welfare plans (such as medical), defined contribution plans (such as 401(k)), or defined benefit plans (such as pension), may adversely affect the demand for, or profitability of, our services.”

Annual report 2025A · The company itself

“Consulting and brokerage also advises multinational companies on global benefits programs, including program design and management, financing optimization, and enhanced employee experience, as well as assists in navigating global regulatory and compliance requirements in over 120 countries.”

Annual report 2025A · The company itself

“Principal Products and Services Risk Capital 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. Commercial Risk Solutions includes insurance and specialty brokerage, global risk consulting, captives management, and Affinity programs.”

Annual report 2025A · The company itself

“Risk Capital Commercial Risk Solutions revenue increased $636 million, or 8%, to $8.5 billion in 2025, compared to $7.9 billion in 2024. Organic revenue growth was 6% in 2025, reflecting strong growth in North America and EMEA, driven by net new business and ongoing strong retention. Performance was highlighted by strong growth in U.S. core P&C and double-digit increases in M&A services and construction.”

Annual report 2025A · The company itself

“We assist our clients with various matters, including advising on and placing insurance and reinsurance coverage and handling related claims, consulting on various human resources matters, and providing actuarial, investment consulting, asset management, and other services.”

Annual report 2025A · The company itself

“Revenue from Contracts with Customers Disaggregation of Revenue The following table summarizes revenue from contracts with customers by principal service line (in millions): Commercial Risk Solutions $ 8,497 $ 7,861 $ 7,043 Reinsurance Solutions 2,793 2,656 2,481 Total Risk Capital (1) 11,290 10,517 9,524 Health Solutions 3,839 3,335 2,433 Wealth Solutions 2,068 1,874 1,431 Total Human Capital (1) 5,907 5,209 3,864 Eliminations (16) (28) (12) Total revenue $ 17,181 $ 15,698 $ 13,376 (1)Includes inter-segment revenue.”

Annual report 2025A · The company itself

“Human Capital Health Solutions revenue increased $504 million, or 15%, to $3.8 billion in 2025, compared to $3.3 billion in 2024. Organic revenue growth was 5% in 2025, reflecting strong growth globally in core health and benefits brokerage, driven by net new business and ongoing strong retention.”

Annual report 2025A · The company itself

“Revenue from Contracts with Customers Disaggregation of Revenue The following table summarizes revenue from contracts with customers by principal service line (in millions): Commercial Risk Solutions $ 8,497 $ 7,861 $ 7,043 Reinsurance Solutions 2,793 2,656 2,481 Total Risk Capital (1) 11,290 10,517 9,524 Health Solutions 3,839 3,335 2,433 Wealth Solutions 2,068 1,874 1,431 Total Human Capital (1) 5,907 5,209 3,864 Eliminations (16) (28) (12) Total revenue $ 17,181 $ 15,698 $ 13,376 (1)Includes inter-segment revenue.”

Annual report 2025A · The company itself

“Principal Products and Services Risk Capital 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. Commercial Risk Solutions includes insurance and specialty brokerage, global risk consulting, captives management, and Affinity programs.”

Annual report 2025A · The company itself

“Risk Capital Commercial Risk Solutions revenue increased $636 million, or 8%, to $8.5 billion in 2025, compared to $7.9 billion in 2024. Organic revenue growth was 6% in 2025, reflecting strong growth in North America and EMEA, driven by net new business and ongoing strong retention. Performance was highlighted by strong growth in U.S. core P&C and double-digit increases in M&A services and construction.”

Annual report 2025A · The company itself

“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.”

Annual report 2025A · The company itself

“Wealth Solutions revenue increased $194 million, or 10%, to $2.1 billion in 2025, compared to $1.9 billion in 2024. 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. Growth in Retirement was driven by continued strong demand for advisory work in the UK and EMEA related to the ongoing impact of regulatory change.”

Annual report 2025A · The company itself

“Principal Products and Services Risk Capital 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. Commercial Risk Solutions includes insurance and specialty brokerage, global risk consulting, captives management, and Affinity programs.”

Annual report 2025A · The company itself

“Revenue from Contracts with Customers Disaggregation of Revenue The following table summarizes revenue from contracts with customers by principal service line (in millions): Commercial Risk Solutions $ 8,497 $ 7,861 $ 7,043 Reinsurance Solutions 2,793 2,656 2,481 Total Risk Capital (1) 11,290 10,517 9,524 Health Solutions 3,839 3,335 2,433 Wealth Solutions 2,068 1,874 1,431 Total Human Capital (1) 5,907 5,209 3,864 Eliminations (16) (28) (12) Total revenue $ 17,181 $ 15,698 $ 13,376 (1)Includes inter-segment revenue.”

Annual report 2025A · The company itself

“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.”

Annual report 2025A · The company itself

“As part of our AAU restructuring program, we are reducing our real estate footprint to align with our hybrid working strategy.”

Annual report 2025A · The company itself

“Revenue from Contracts with Customers Disaggregation of Revenue The following table summarizes revenue from contracts with customers by principal service line (in millions): Commercial Risk Solutions $ 8,497 $ 7,861 $ 7,043 Reinsurance Solutions 2,793 2,656 2,481 Total Risk Capital (1) 11,290 10,517 9,524 Health Solutions 3,839 3,335 2,433 Wealth Solutions 2,068 1,874 1,431 Total Human Capital (1) 5,907 5,209 3,864 Eliminations (16) (28) (12) Total revenue $ 17,181 $ 15,698 $ 13,376 (1)Includes inter-segment revenue.”

Annual report 2025A · The company itself

“Our operations are dependent upon our ability to protect our personnel, offices, and technology infrastructure against damage from business continuity events that could have a significant disruptive effect on our operations. Should we experience a local or regional disaster or other business continuity problem, such as a security or cyber incident or attack, a natural disaster, climate event, terrorist attack, pandemic, power loss, telecommunications failure, or other natural or human-caused disaster, our continued success will depend, in part, on the availability of our personnel and office facilities, and the proper functioning of computer systems, telecommunications, and other related systems and operations.”

Annual report 2025A · The company itself

“An interruption in or 22 the cessation of service by any service provider as a result of systems failures, cybersecurity or data privacy incidents (including, but not limited to, ransomware), capacity constraints, financial difficulties, or for any other reason could disrupt our 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.”

Annual report 2025A · The company itself

“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. We rely on the efficient, uninterrupted, and secure operation of complex information technology systems and networks, some of which are within the Company and some of which are outsourced to third parties. All information technology systems are potentially vulnerable to damage or interruption from a variety of sources, including but not limited to cyber-attacks, malicious or destructive code, ransomware, social engineering attacks, generative artificial intelligence and deepfake attacks, denial of service attacks, data and security breaches, and unauthorized access or improper actions by third parties with whom 23 we engage, insiders or employees.”

Annual report 2025A · The company itself

“We are at risk of attack by a growing list of adversaries through new and increasingly sophisticated methods of attack, including methods that take advantage of remote work scenarios and evolving geopolitical risks. Because the techniques used to obtain unauthorized access or sabotage systems change frequently , we may be unable to anticipate these techniques, implement and maintain adequate preventative measures, or detect respond, and if required, disclose to third parties quickly enough in the event of an incident or attack.”

Annual report 2025A · The company itself

“We regularly experience social engineering attempts, and increasingly sophisticated attempted attacks to our systems and networks, certain of which have been successful and have resulted in unauthorized access to our systems and data. Aon has from time to time experienced cybersecurity incidents, such as malicious or destructive code, unauthorized parties gaining access to our information technology systems, ransomware incidents, data loss via malicious and non-malicious methods, and similar incidents, which to date have not had a material impact on our business.”

Annual report 2025A · The company itself

“Aon has from time-to-time experienced and may experience in the future problems with the information technology systems of vendors, including breakdowns or other disruptions in communication services provided by a vendor, failure of a vendor to handle current or higher volumes, difficulties in the migration of services or data to third parties or the cloud hosted by third parties, cyber-attacks, and security breaches, any of which could adversely affect our ability to deliver products and services to customers and otherwise conduct business.”

Annual report 2025A · The company itself

“We have implemented various measures to manage our risks related to system and network security and disruptions, but a security breach or a significant or extended disruption in the functioning of our information technology systems could damage our reputation, cause us to lose clients, adversely impact our operations, sales, and operating results, and require us to incur significant expense (in connection with incident response, remediation efforts, or otherwise) and divert resources to address and remediate or otherwise resolve such issues. Additionally, in order to maintain the level of security, service, and reliability that our clients require, we may be required to make significant additional investments in our information technology systems.”

Annual report 2025A · The company itself

“Additionally, we are a global and acquisitive organization and we therefore may not adequately identify weaknesses in certain of our information systems, including those of targets we acquire, which could expose us to unexpected liabilities and fines or make our own systems more vulnerable to attack. These types of incidents affecting us, our clients, insurance carriers, vendors, or other third-parties could result in intellectual property or other confidential information being lost or stolen, including client or employee personal information or company data.”

Annual report 2025A · The company itself

“Financial Risks •We are exposed to fluctuations in currency exchange rates that could negatively impact our financial results and cash flows.”

Annual report 2025A · The company itself

“A reconciliation of this non-GAAP measure to the reported Cash provided by operating activities is as follows (in millions): Years Ended December 31 2025 2024 Cash provided by operating activities $ 3,481 $ 3,035 Capital expenditures (263) (218) Free cash flow $ 3,218 $ 2,817 Impact of Foreign Currency Exchange Rate Fluctuations Because we conduct business in over 120 countries, foreign exchange rate fluctuations may have a significant impact on our business. Foreign exchange rate movements may be significant and may distort true period-to-period comparisons of changes in revenue or pretax income. Therefore, to give financial statement users meaningful information about our operations, we have provided an illustration of the comparable impact of foreign currency exchange rates on our financial results.”

Annual report 2025A · The company itself

“Risks Related to Technology, Cybersecurity, and Data Protection •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. •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.”

Annual report 2025A · The company itself

“The demand for property and casualty insurance generally rises as the overall level of economic activity increases and generally falls as such activity decreases, affecting both the commissions and fees generated by our Risk Capital segment. The economic activity that impacts property and casualty insurance is most closely correlated with employment levels, corporate revenues, and asset values.”

Annual report 2025A · The company itself

“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 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.”

Annual report 2025A · The company itself

“These losses may be attributable in whole or in part to alleged failures on our part or to events entirely outside of our control, including but not limited to uncertainty or volatility in financial markets due to economic, political, and regulatory conditions or pandemics.”

Annual report 2025A · The company itself

“Our operations in countries undergoing political change or experiencing economic instability are subject to uncertainty and risks that could materially adversely affect our business. These risks include, particularly but not limited to in emerging markets, the possibility we would be subject to undeveloped or evolving legal systems, unstable governments and economies, impacts from geopolitical conflicts, and potential governmental actions affecting the flow of goods, services, currency and particular sectors or entities.”

Annual report 2025A · The company itself

“We are at risk of attack by a growing list of adversaries through new and increasingly sophisticated methods of attack, including methods that take advantage of remote work scenarios and evolving geopolitical risks. Because the techniques used to obtain unauthorized access or sabotage systems change frequently , we may be unable to anticipate these techniques, implement and maintain adequate preventative measures, or detect respond, and if required, disclose to third parties quickly enough in the event of an incident or attack.”

Annual report 2025A · The company itself

“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 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.”

Annual report 2025A · The company itself

“We are exposed to various risks arising out of natural disasters, including earthquakes, hurricanes, fires, floods, droughts, tornadoes, extreme weather, or other climate events; pandemic health events (such as the COVID-19 pandemic), and human-caused disasters, including acts of terrorism, civil unrest, violence, military actions, and cyber-terrorism (including, but not limited to, ransomware).”

Annual report 2025A · The company itself

“If access to underwriting markets for certain lines of coverage becomes unavailable or difficult due to the impact of climate change on the claims environment, this may have a negative impact on our clients’ access to coverage, which could in turn reduce our ability to place certain lines of coverage and negatively impact our business.”

Annual report 2025A · The company itself

“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 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.”

Annual report 2025A · The company itself

“These losses may be attributable in whole or in part to alleged failures on our part or to events entirely outside of our control, including but not limited to uncertainty or volatility in financial markets due to economic, political, and regulatory conditions or pandemics.”

Annual report 2025A · The company itself

“We are exposed to various risks arising out of natural disasters, including earthquakes, hurricanes, fires, floods, droughts, tornadoes, extreme weather, or other climate events; pandemic health events (such as the COVID-19 pandemic), and human-caused disasters, including acts of terrorism, civil unrest, violence, military actions, and cyber-terrorism (including, but not limited to, ransomware).”

Annual report 2025A · The company itself

“Our businesses are subject to extensive legal and regulatory oversight throughout the world, including the Irish Companies Act, the U.S. securities laws, rules, and regulations, the rules and regulations promulgated by the FCA and a variety of other laws, rules, and regulations addressing, among other things, licensing, data privacy, data management and data protection, artificial intelligence, trade sanctions laws, restrictions and export controls, anti-money laundering, wage-and-hour standards, employment and labor relations, antitrust and competition, anti-corruption, currency, reserves, government contracting, and the amount of local investment with respect to our operations in certain countries.”

Annual report 2025A · The company itself

“Changes in laws and regulations could mandate significant and costly changes to the way we implement our services and solutions, impose additional licensure requirements or costs to our operations, workforce and services, or cause us to cease offering certain services or solutions.”

Annual report 2025A · The company itself

“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.”

Annual report 2025A · The company itself

“Our cost efficiencies may also be impacted by factors such as our ability to transition consultants from completed projects to new assignments, to secure new business, to forecast demand for our services (and, consequently, appropriately manage the size and location of our workforce), to develop, attract and retain suitable capabilities and talent, to obtain third party services at favorable prices, and to manage key suppliers to maximize delivery; product and efficiency opportunities; inflation (including wage inflation); and the need to devote time and resources to training and professional and business development.”

Annual report 2025A · The company itself

“During 2012, the Company was granted a tax holiday for the period from October 1, 2012 through September 30, 2022, with respect to withholding taxes and certain income derived from services in Singapore. The Company has been granted a new incentive for the period October 1, 2022 to September 30, 2032. The new incentive provides for a reduced withholding tax rate and a reduced tax rate on certain income derived from services in Singapore, as long as certain conditions are met.”

Annual report 2025A · The company itself

“Leases The Company leases office facilities, equipment, and automobiles under operating leases. The Company’s lease obligations are primarily for the use of office facilities.”

Annual report 2025A · The company itself

“At December 31, 2025, Cash and cash equivalents and Short-term investments totaled $2.8 billion compared to $1.3 billion at December 31, 2024, an increase of $1.5 billion.”

Annual report 2025A · The company itself

“Organic revenue growth was 6% in 2025, reflecting strong growth in North America and EMEA, driven by net new business and ongoing strong retention. Performance was highlighted by strong growth in U.S. core P&C and double-digit increases in M&A services and construction.”

Annual report 2025A · The company itself

“Organic revenue growth was 6% in 2025, reflecting strong growth in North America and EMEA, driven by net new business and ongoing strong retention. Performance was highlighted by strong growth in U.S. core P&C and double-digit increases in M&A services and construction.”

Annual report 2025A · The company itself