AON, Aon PLC
We serve clients in more than 120 countries across all market segments and nearly every industry.
Read top to bottom, the owner's questions in the order an owner asks them: what the business is, whether the record holds, whether it survives and is any good, and what you would be paying. New to the questions? Start with the Method.
The business in brief
read the 10-K →What this business is and what moves its needle, read from the numbers in its filings. The quantitative detail is in the sections below; the verdict is left to you.
- What it is
- An insurance business, read on its underwriting result, the combined ratio, and the float it invests, rather than an earnings multiple.
- What moves the needle
- Underwriting discipline and the float. What decides it: whether the combined ratio stays below 100% so the policies make money on their own, how large the float is against equity, and what that float earns once it is invested.
- Is it a good business?
- The underwriting result is not cleanly tagged in the filings. Book value per share, the measure Berkshire is judged on, has compounded about 9% a year across the record. Whether the discipline holds through a soft market, and how the float is invested, are what the 10-K decides.
Every line here is arithmetic from the company's own filings, not a model's opinion, and each figure appears in full in the sections below.
Where the money comes from
read the 10-K →52% of revenue comes from outside the United States.
- United States48%$8.3B
- Europe, Middle East, & Africa other than U.K. and Ireland18%$3.2B
- United Kingdom13%$2.2B
- Asia Pacific10%$1.7B
- Americas other than U.S.10%$1.6B
- Ireland1%$185M
From the segment footnote of the company's own 10-K. Shares are of total revenue; the profit bar shows each segment's share of segment operating profit, before unallocated corporate costs.
The record, 2016–2025
realized figures from each filing, no estimates| 2016’16 | 2017’17 | 2018’18 | 2019’19 | 2020’20 | 2021’21 | 2022’22 | 2023’23 | 2024’24 | 2025’25 | TTMTTMMar 2026 | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| RevenueRevenue | $9.4B | $10.0B | $10.8B | $11.0B | $11.1B | $12.2B | $12.5B | $13.4B | $15.7B | $17.2B | $17.5B |
| Net incomeNet inc. | $1.4B | $1.2B | $1.1B | $1.5B | $2.0B | $1.3B | $2.6B | $2.6B | $2.7B | $3.7B | $3.9B |
| Return on equityROE | 25% | 27% | 27% | 45% | 56% | 118% | -489% | -310% | 43% | 40% | 40% |
| Book value / shareBVPS | $20.26 | $17.58 | $16.81 | $14.03 | $14.99 | $4.69 | $-2.48 | $-4.03 | $28.80 | $43.08 | $45.65 |
| Dividends / shareDiv/sh | $1.28 | $1.40 | $1.55 | $1.70 | $1.77 | $1.98 | $2.17 | $2.39 | $2.64 | $2.90 | — |
Owner’s Scorecard
Is it a good business?
- Not enough data
Premiums or claims weren't found in the filing data.
- Return on equity 40%StrongNet income $3.7B ÷ equity $9.4B
What it earns on shareholders' capital, the underwriting result plus what the float earns invested. Durably above the ~10% cost of equity is what compounds book value.
The float
- Float —Not enough data
Loss reserves weren't found.
- Not enough data
Net investment income wasn't found.
Solvent is not the same as cheap; growing is not the same as good. These are vital signs, not a verdict, the judgment is yours, and the filing is one click away.
Management & pay
Two questions Buffett actually asks about pay: is stock compensation, a real expense, whatever the income statement pretends, quietly large, and is the top wildly out of line with the floor. He's no populist about it; he just wants pay that's rational and earned, and comp committees that aren't lapdogs.
- Stock-based compensation$432M
The slice of the business handed to employees in shares this year, 3% of revenue, equal to 10% of operating profit. Buffett's oldest accounting fight: this is compensation, compensation is an expense, real whether or not the headline earnings admit it. And note the trap, the cash-flow statement adds SBC back, so the operating cash, and the owner earnings drawn from it, are flattered by exactly this amount; counted as the cost it is, what an owner keeps is lower.
What the price implies
reverse-DCFA bank / financial isn't read on an owner-earnings DCF, its economics live on the balance sheet (book value, the return earned on it, and the cash the assets throw off). We don't force this lens where it doesn't belong.
What the filing emphasizes, FY2025
read the 10-K →Each year a 10-K must name what could go wrong, in the company's own words. Here are the ones Graham and Buffett would stop on, each set against the figure from the same filings that bears on it, anchored to a period you can find in the record above. We point; the judgment is yours.
- Pricing power & competitionBusiness
Whether the company sets its price or takes it. Durable pricing power is the surest mark of a moat; price competition is the surest mark there isn't one.
“By removing some of the traditional barriers to entry-level employment, as a firm we can contribute to local workforce development and cultivate talent while improving retention rates in these entry-level roles.”
From the recordOperating margin26.3% now (TTM), off a 29.4% peak (FY2022) - Concentrated dependenceRisk Factors
What the whole business leans on, a product, a platform, a partner. Concentration cuts both ways, and the filing is where management has to admit it.
“We face exposure to adverse movements in exchange rates of currencies other than our reporting currency, the U.S. dollar, as a significant portion of our business is located outside of the U.S.”
From the recordOwner-earnings margin at stake (TTM)20% - Debt terms & refinancingMD&A
The fine print behind the debt. Covenants and near-term maturities decide who is really in control when a year goes badly.
“Each of these primary committed credit facilities includes customary representations, warranties, and covenants, including financial covenants that require us to maintain specified ratios of adjusted consolidated EBITDA to consolidated interest expense and consolidated debt to adjusted consolidated …”
From the recordBalance sheet (TTM)$12.5B meaningful net debt · interest covered 5.3× - Litigation & contingenciesRisk Factors
Claims an owner inherits. Most disclosure is boilerplate; this fires only on an actual matter, a named suit, a settlement, a contingency, a number.
“Plaintiffs have filed, and may continue to file, individual and class action lawsuits alleging investment consultants have charged excessive fees, given improper advice or taken investment actions due to conflicts of interest, or recommended investments that underperformed other investments availabl…”
A judgment, not a number, weigh it against the filing yourself. - Cyclicality & demandRisk Factors
How the business behaves when the economy turns. A cyclical earns its keep across the whole cycle, not at the peak.
“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.”
From the recordWorst year on record10.7% operating margin (FY2017) - Regulation & policyMD&A
Rules that can rewrite the economics, tariffs, antitrust, data, export controls.
“Preparation of forecasts and selection of the discount rate for use in the DCF model involve significant judgments, and changes in these estimates could affect the estimated fair value of one or more of our reporting units and could result in a goodwill impairment charge in a future period.”
A judgment, not a number, weigh it against the filing yourself.
What changed, FY2025 vs FY2024
read the 10-K →Most of a 10-K is boilerplate carried over verbatim; the signal is in what's new. These lines appear this year and weren't there last, figure updates filtered out, so only the language shift remains.
- “In the fourth quarter of 2023, Aon recognized a $197 million charge in connection with transactions for which capital was arranged by a third party, Vesttoo Ltd., and in the third quarter of 2025, certain legal settlement expenses and recoveries were recognized resulting in a $23 million reduction o…”
- “For the Year Ended December 31 2025 2024 Risk Capital 10 10 Human Capital 8 12 Total 18 22 For the year ended December 31, 2025, cash consideration, net of cash and funds held on behalf of clients acquired, was $394 million, which relates to cash consideration paid in 2025 for current year acquisiti…”
- “Cash flows provided by operating activities was $3.5 billion in 2025, an increase of $446 million, or 15%, from $3.0 billion in 2024, due primarily to strong adjusted operating income growth and lower NFP-related transaction costs, partially offset by working capital headwinds.”
- “For the Year Ended December 31 2025 2024 Risk Capital 1 3 Human Capital 3 2 Total 4 5 For the year ended December 31, 2025, cash consideration for dispositions, net of cash and funds held on behalf of clients, was $2.3 billion.”
- “Risks Related to Being an Irish-incorporated Company 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. 10 As an Irish public limited company, certain capital structure decisions regarding the Company…”
Classic text analysis over the filing itself, no model wrote a word of this, and every quote is the company's own.
Peers, Insurance brokers
The same industry, side by side on the underwriting lens, compare, don't rank by a single number.● marks best in the group.
| Company | Revenue | Combined ratio | Loss ratio | ROE |
|---|---|---|---|---|
| AONAon PLC | $17.2B | — | — | 40% |
| AJGArthur J. Gallagher & Co. | $13.9B | — | — | 6% |
| WTWWillis Towers Watson PLC | $9.5B | — | — | 20% |
| BROBrown & Brown, Inc. | $5.9B | — | — | 8% |