Aon plc (AON)

Aon plc is a leading global professional services firm that provides risk and people advice and solutions to help clients make better decisions and protect and grow their businesses. It combines analytic insight with Risk Capital and Human Capital expertise under its Aon United strategy, which aims to serve clients as one globally connected firm. The company focuses on higher-margin, capital-light professional services businesses with high recurring revenue and strong cash flow. It generates revenue mainly through commissions, fees from clients for advice and consulting, and compensation from insurers and reinsurers for services provided to them. In 2025, total revenue was $17,181 million.

Aon reports two segments: Risk Capital, with $11,290 million of revenue, and Human Capital, with $5,907 million, both before certain intercompany eliminations. Risk Capital includes Commercial Risk Solutions (insurance and specialty brokerage, global risk consulting, captives management and Affinity programs) and Reinsurance Solutions (treaty and facultative reinsurance, the Strategy and Technology Group with modeling tools such as ReMetrica and PathWise, and a capital markets investment bank covering insurance-linked securities, capital raising and M&A advice). Human Capital includes Health Solutions (health and benefits consulting and brokerage, consumer benefits, compensation and talent advisory, and sustainability consulting) and Wealth Solutions (retirement consulting, pension administration, pension risk transfer, and investments consulting, including delegated investment solutions, Master Trusts and Pooled Employer Plans).

Aon serves clients in more than 120 countries across all market segments and nearly every industry, including corporations, insurers, reinsurers, public pensions, endowments and foundations. This diversification helps provide stability across economic scenarios. Its largest client accounted for about 1% of 2025 revenue, and no insurance carrier accounted for more than 10% of premiums placed for clients. Revenues tend to be higher in the first and fourth quarters because of buying patterns. The company also holds funds on behalf of clients, such as premiums and claims in transit, in segregated premium trust accounts.

Aon operates in a highly competitive, fragmented market, competing with Marsh McLennan, Willis Towers Watson, Arthur J Gallagher & Company, Lockton Companies and many global, regional and local firms. It also competes with insurers and reinsurers that sell directly, large financial institutions, and independent or affiliated consulting organizations. Its Global Broking Centers are in London, Bermuda and Singapore. The business is subject to extensive licensing and regulation, including by the FCA in the U.K., the SEC, DOL and FINRA in the U.S., and authorities in other countries. Its U.S. broker-dealer subsidiary, Aon Securities LLC, handles investment banking and capital advisory services. As of December 31, 2025, Aon employed approximately 60,000 people.