Aon PLC (NYSE: AON) is a professional services company that provides insurance brokerage, reinsurance brokerage, and consulting services to organizations across risk, health, and retirement. Revenue comes primarily from commissions and fees earned when placing insurance and reinsurance coverage on behalf of clients, supplemented by fees for consulting, analytics, and advisory services. Aon competes directly with Marsh McLennan, Willis Towers Watson, Arthur J. Gallagher, and Lockton Companies, as well as regional brokers, direct-writing insurers, large financial institutions, and consulting firms affiliated with accounting and technology organizations (per the FY2025 10-K filed 2026-02-13). The company is incorporated in Ireland and operates globally, advising multinational companies on benefits programs across more than 120 countries. As of December 31, 2025, Aon employed a global workforce that included operations subject to regulatory oversight from the FCA in the U.K., the SEC and DOL in the U.S., and insurance regulators across multiple jurisdictions. The single largest client by revenue accounted for less than 10% of total revenue (FY2025 10-K).

Revenue model

Commissions and fees from placing commercial insurance, reinsurance, and specialty coverage; consulting and advisory fees for health, benefits, and retirement services; and analytics and data-driven advisory engagements. Aon holds client premiums and claims in transit in interest-bearing premium trust accounts, earning interest on those balances, though the principal is segregated and not available for general operating use.

Products and services

Commercial Risk Solutions: insurance and specialty brokerage, global risk consulting, captives management, and Affinity programs, organized around property, casualty, financial and professional lines, construction, transportation, energy, cyber, surety, trade credit, crisis management, transaction liability, and climate. Health Solutions: health and benefits consulting and brokerage, consumer benefits programs delivered via a proprietary digital enrollment platform, compensation and talent advisory. Reinsurance Solutions and Wealth Solutions segments are referenced in the filing. Aon Securities LLC, a FINRA-member broker-dealer and registered investment advisor, provides investment banking and capital advisory services.

Customers and end markets

Corporations and multinational companies seeking commercial insurance placement and risk management. Employers purchasing health, benefits, and retirement consulting. No single client accounted for 10% or more of total revenue (FY2025 10-K). Clients span virtually all industries and geographies.

Value-chain role

Intermediary and advisor sitting between insurance buyers (corporate clients) and insurance and reinsurance capital providers. Aon designs programs, places risk, and provides analytics rather than underwriting or retaining insurance risk itself.

Geographic exposure

Global operations with regulatory oversight in Ireland, the United Kingdom, the United States, and numerous other countries. Health consulting advises clients on global benefits programs in over 120 countries. EMEA referenced as a defined operating region in the filing.

Competitors

Marsh McLennan, Willis Towers Watson, Arthur J. Gallagher & Company, Lockton Companies, Inc., Regional and local insurance brokers, Direct-writing insurance and reinsurance companies, Large financial institutions, Independent consulting firms, Consulting organizations affiliated with accounting, information systems, technology, human resources, and financial services firms

Source: SEC 10-K, filed 2026-02-13

Industry: Insurance Agents, Brokers & Service