Aon plc

Aon's client retention has run in the mid-90s consistently, meaning the majority of commissions and fees recur each year as clients renew existing coverage programs. Annual renewals on legally required insurance placements, reinforced by embedded risk analytics programs, create strong forward revenue visibility across commercial risk and reinsurance lines.

Risk Capital (Commercial Risk and Reinsurance Solutions) comprised roughly 66% of FY2025 revenue and Human Capital (Health and Wealth) comprised 34%, representing genuine diversification across four distinct business lines. The two Risk Capital sub-segments are correlated within an insurance market cycle, which limits truly uncorrelated diversification despite the breadth of offerings.

Aon generated approximately 48% of FY2025 revenue from the US and 52% internationally, serving clients across 120+ countries with meaningful revenue from EMEA, Asia-Pacific, and the Americas outside the US. The near-equal US/international split is broadly balanced for a financial services firm of this scale, though the US remains the single-largest geographic exposure.

Aon's adjusted operating margin expanded to 32.4% for full-year FY2025 (up 90 basis points from the FY2024 combined baseline), as the asset-light brokerage model spreads Aon Business Services technology and back-office costs across a growing revenue base. The professional services core remains people-intensive, placing a natural ceiling on incremental operating leverage relative to pure platform businesses.

Aon earns commissions and advisory fees on placements of insurance and reinsurance that clients are legally or contractually required to maintain, creating a fundamentally non-discretionary revenue stream with limited sensitivity to corporate budget cycles. Risk Capital at 66% and Human Capital at 34% of FY2025 revenue both reflect mission-critical advisory work rather than discretionary project spending.