Major ClientsNarrow moat

American Express (AXP) — moat facet

American Express has no large customers and a few very large partners, whose cards carry a quarter of the spending and more than a third of the loans.

American Express has no revenue concentration of the ordinary kind. Its annual report contains no table of customers above 10% of revenue, and its most significant concentration of credit risk is "individuals in the aggregate"1. Proprietary cards-in-force were 86.6 million at the end of 20252.

Worldwide billed business by card type, 2025 ($bn)Delta cobrand — 13%Other cobrands — 13%Proprietary cards — 74%Calculated from American Express Form 10-K FY2025 shares (13%, 26%) of $1,669.8bn
A quarter of the spending runs on partner cards.

The concentration is elsewhere: in partners. Cobrand cards carried about 26% of worldwide billed business and about 36% of Card Member loans in 20253, and one partner, Delta, about 13% and 21%4. Revenue concentration and loan concentration differ sharply, and it is the loans that would leave with a partner.

There is a second concentration by kind of customer. Spending by small business and corporate clients was about 41% of worldwide billed business in 20255, and the commercial business behaves differently from the consumer one, slowing first when companies cut travel.

Four pages follow: Delta, the cobrand group as a whole, the Costco precedent and the portfolios Amex is choosing to leave.

The two concentrations point the same way. A cardholder is diversified; a partner is not. The largest risk on this page is not that customers leave one by one, which they rarely do, but that a partner takes several million of them at once, as Costco did in 20166.

The concentration shows up in the cash flows of the partners as well as in Amex's own disclosures. Delta says substantially all of its cash sales from loyalty marketing agreements relate to its cobrand card with American Express, and those cash sales were $6.9 billion in 2023, $7.4 billion in 2024 and $8.0 billion in 20257. Delta depends on the cash; Amex depends on the spending. That mutual dependence is what makes the 2029 renewal a negotiation between two parties who both need a deal.

The card balances show the customer mix in dollars. At the end of June 2026 Amex carried $218,054 million of card balances: $144,974 million from consumers, $56,172 million from small businesses and $16,908 million from corporate clients8. The consumer book is about two-thirds of the total9, and it is where most of the credit risk sits.

The geography of the customers adds a third layer. Card Members in California, Florida, New York, Texas, Georgia and New Jersey account for what the company calls "a significant portion of U.S. consumer and small business billed business and Card Member loans"10, so even a diversified base of individuals is concentrated in a handful of states.

The share of billed business on cobrand cards is the number that summarises it. It rose from about 18% in 201911 to about 26% in 202512; a figure above 30% would mean close to a third of the spending depended on contracts that end.

Moat trajectory: Narrowing

Cobrands 26% of billed business and 36% of loans (2025); Delta 13% and 21%.

The number that tests this moat
Reported
Small business and corporate share of billed business
About 41% (2025)

The commercial customer mix; a fall would mean the business customers who travel most were spending less.

Source: American Express Form 10-K, FY2025 ↗
Dig deeper
DIG DEEPER 01
Delta: Thirteen Percent of the Spending
Delta cards carry about 13% of American Express spending and 21% of its loans, and Delta says it was paid $8.2 billion for them in 2025.
DIG DEEPER 02
Twenty-Six Percent Through Partners
More than a third of American Express's card loans sit on cards that carry someone else's name and could leave with that partner.
DIG DEEPER 03
Costco: What Losing a Partner Looks Like
The Costco exit took a fifth of American Express's loans, and Delta is now a larger partner than Costco ever was.
DIG DEEPER 04
Amazon and Lowe's: The Partners Amex Let Go
American Express chose to let its Amazon and Lowe's small-business cards go, and pays for the discipline with a year of slower interest income.
References
  1. ReportedIts annual report contains no table of customers above 10% of revenue, and its most significant concentration of credit risk is "individuals in the aggregate".
    American Express Form 10-K for fiscal 2025 - income statement, business description and management. — FY2025 · publ. 6 February 2026 · source ↗
  2. ReportedProprietary cards-in-force were 86.6 million at the end of 2025.
    American Express Form 10-K for fiscal 2025 - card metrics: billed business, spending per card, cards-in-force, fees per card and network volumes. — FY2025 · publ. 6 February 2026 · source ↗
  3. ReportedCobrand cards carried about 26% of worldwide billed business and about 36% of Card Member loans in 2025, and one partner, Delta, about 13% and 21%.
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  4. ReportedCobrand cards carried about 26% of worldwide billed business and about 36% of Card Member loans in 2025, and one partner, Delta, about 13% and 21%.
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  5. ReportedSpending by small business and corporate clients was about 41% of worldwide billed business in 2025, and the commercial business behaves differently from the consumer one, slowing first when companies cut travel.
    American Express Form 10-K for fiscal 2025 - card metrics: billed business, spending per card, cards-in-force, fees per card and network volumes. — FY2025 · publ. 6 February 2026 · source ↗
  6. ReportedThe largest risk on this page is not that customers leave one by one, which they rarely do, but that a partner takes several million of them at once, as Costco did in 2016.
    American Express Form 10-K for fiscal 2015 - the end of the Costco relationship and its share of billed business, loans and cards; the three-party network; average discount rates 2013-2015. — FY2015 · publ. February 2016 · source ↗
  7. ReportedDelta says substantially all of its cash sales from loyalty marketing agreements relate to its cobrand card with American Express, and those cash sales were $6.9 billion in 2023, $7.4 billion in 2024 and $8.0 billion in 2025.
    Delta Air Lines Form 10-K for fiscal 2025 - remuneration from American Express and the jet fuel purchasing card. — FY2025 · publ. February 2026 · source ↗
  8. ReportedAt the end of June 2026 Amex carried $218,054 million of card balances: $144,974 million from consumers, $56,172 million from small businesses and $16,908 million from corporate clients.
    American Express second-quarter 2026 statistical supplement, Form 8-K exhibit 99.2 - segment results, card metrics, capital and credit - consolidated results, card metrics, capital and credit. — Q2 2026 · publ. 24 July 2026 · source ↗
  9. Moat Explorer calcThe consumer book is about two-thirds of the total, and it is where most of the credit risk sits.
    Moat Explorer calculation from American Express's reported figures ($ millions unless stated). Incentives (variable customer engagement costs = Card Member rewards + business development + Card Member services): 2021 11,007 + 3,762 + 1,993 = 16,762; 2022 14,002 + 4,943 + 2,959 = 21,904; 2023 15,367 + 5,657 + 3,968 = 24,992; 2024 16,599 + 5,886 + 4,782 = 27,267; 2025 18,409 + 6,457 + 6,057 = 30,923; Q2 2026 5,051 + 1,755 + 1,949 = 8,755; Q2 2025 7,508. As a share of discount revenue: 16,762 / 24,563 = 68.2%; 21,904 / 30,739 = 71.3%; 24,992 / 33,416 = 74.8%; 27,267 / 35,192 = 77.5%; 30,923 / 37,401 = 82.7%; Q2 2026 8,755 / 10,163 = 86.1%; Q2 2025 7,508 / 9,361 = 80.2%. Discount revenue left after incentives: 24,563 - 16,762 = 7,801; 30,739 - 21,904 = 8,835; 33,416 - 24,992 = 8,424; 35,192 - 27,267 = 7,925; 37,401 - 30,923 = 6,478; Q2 2026 10,163 - 8,755 = 1,408; Q2 2025 9,361 - 7,508 = 1,853. Incentives / total revenue 16,762 / 42,380 = 39.6%; 30,923 / 72,229 = 42.8%. Incentive growth 30,923 / 16,762 - 1 = 84%; 30,923 / 27,267 - 1 = 13.4%. Discount revenue growth 37,401 / 24,563 - 1 = 52%; 37,401 / 35,192 - 1 = 6.3%. Rewards 18,409 / 11,007 - 1 = 67%; rewards / discount revenue 11,007 / 24,563 = 44.8%; 14,002 / 30,739 = 45.6%; 15,367 / 33,416 = 46.0%; 16,599 / 35,192 = 47.2%; 18,409 / 37,401 = 49.2%. Business development 6,457 / 3,762 - 1 = 72%; / discount revenue 3,762 / 24,563 = 15.3%, 6,457 / 37,401 = 17.3%. Card Member services 6,057 / 1,993 = 3.04 times (+204%); 6,057 / 1,392 = 4.35; growth 3,968 / 2,959 - 1 = 34.1%; 4,782 / 3,968 - 1 = 20.5%; 6,057 / 4,782 - 1 = 26.7%; 6,057 / 2,959 = 2.05. Card Member services / net card fees 1,993 / 5,195 = 38%; 3,968 / 7,255 = 55%; 6,057 / 9,993 = 61%; Q2 2026 1,949 / 2,862 = 68%. Membership Rewards liability 16.5 billion / equity 33,474 = 49%; URR +1 point = 4 x 229 = 916. Card fees: 9,993 / 4,042 = 2.47 (+147%); 9,993 / 5,195 - 1 = 92%; growth 6,070 / 5,195 - 1 = 16.8%, 7,255 / 6,070 - 1 = 19.5%, 8,449 / 7,255 - 1 = 16.5%, 9,993 / 8,449 - 1 = 18.3%; added 9,993 - 8,449 = 1,544. Share of revenue 4,042 / 43,556 = 9.3%; 5,195 / 42,380 = 12.3%; 7,255 / 60,515 = 12.0%; 9,993 / 72,229 = 13.8%. Average fee per card 131 / 58 = 2.26; 117 / 103 - 1 = 14%. Proprietary cards 86.6 / 70.3 - 1 = 23%. Marketing 6,252 / 12.5 million new cards = about $500; 6,252 / 1,544 = 4.0. Card fees plus net interest income (9,993 + 17,364) / 72,229 = 38%. Spending per card 23,496 / 20,392 - 1 = 15.2%; 24,059 / 23,496 - 1 = 2.4%; 24,608 / 24,059 - 1 = 2.3%; 25,453 / 24,608 - 1 = 3.4%. Billed business 1,669.8 / 1,070.5 - 1 = 56%; 1,669.8 / 1,550.9 - 1 = 7.7%; 870.7 / 1,070.5 - 1 = -18.7%. Network volumes 1,897.0 / 1,265.7 - 1 = 50%; 1,897.0 - 1,669.8 = 227.2. Merchant rate 2.51% - 2.24% = 0.27 points x 1,669.8 billion = about 4.5 billion; 4.5 / 37.4 = 12%. Pretax income 13,795 - 10,689 = 3,106. Revenue mix 2019: discount 26,167 / 43,556 = 60.1%; net interest income 8,620 / 43,556 = 19.8%; 2025: 37,401 / 72,229 = 51.8%; 17,364 / 72,229 = 24.0%. Net interest income 17,364 / 7,750 = 2.24; 17,364 / 8,620 - 1 = 101%; +100bp +19 / 17,364 = 0.1%. Card Member loans 151,832 / 87,400 - 1 = 74%. Held for sale 2,457 / 151,832 = 1.6%. Revenue 2020 36,087 / 43,556 - 1 = -17%. Deposits 152,488 / 210,300 = 72.5%; 156,973 / 152,488 - 1 = 2.9%. Delta: 13% x 1,669.8 = 217 billion; 8.2 billion / net income 10,833 = 76%; 8.2 / net card fees 9,993 = 82%; 8.2 / 7.4 - 1 = 11%. Other cobrands 26% - 13% = 13% x 1,669.8 = 217; proprietary 74% x 1,669.8 = 1,236. Valuation: market value 206.30 / 254.84 - 1 = -19%; P/E 206.30 / trailing net income 11.446 = 18.0; P/S 206.30 / 75.95 = 2.72; end-2025 254.84 / 10.833 = 23.5; end-2015 68.45 / 5.163 = 13.3; earnings yield 1 / 23.5 = 4.3%. Trailing twelve months to June 2026: revenue 72,229 + 38,544 - 34,823 = 75,950; net income 10,833 + 6,082 - 5,469 = 11,446; EPS 15.38 + 8.81 - 7.71 = 16.48. Diluted shares 696 / 1,003 - 1 = -30.6%. Net income 10,833 / 5,163 = 2.10; EPS 15.38 / 5.05 = 3.05. Berkshire 151.61 million / 675 million = 22.5%; 13F shares 1,149,942 + 149,061,045 + 1,399,713 = 151,610,700, value 388,967,882 + 50,419,898,471 + 473,452,922 = $51.28 billion (30 June 2026). Card balances consumer 144,974 / 218,054 = 66%. Card fees / discount revenue 9,993 / 37,401 = 27% (2025), 4,042 / 26,167 = 15% (2019). Marketing plus incentives 6,252 + 30,923 = 37,175. Provisions / net interest income 5,256 / 17,364 = 30%. Card Member loans growth 139,674 / 125,995 - 1 = 11%; 151,832 / 139,674 - 1 = 9%; billed business 1,550.9 / 1,459.6 - 1 = 6%. Price to book 305.50 / 48.42 = 6.3. Receivables 62,031 / (151,832 + 62,031) = 29%. GMNS Q2 2026 pretax 1,128 / 1,054 - 1 = 7%. Dividend yield 3.80 / 305.50 = 1.2%. Discount revenue at the 2013 rate 2.51% x 1,669.8 = 41.9 billion; each basis point of rate 0.0001 x 1,669.8 billion = 167 million (5bp 835, 10bp 1,670). Merchant locations at the start of 2026 about 190 - 20 = 170 million. Card Member services growth 2021-2025 +204% against net card fees +92%. A 2020-sized fall today: 18.7% x 1,669.8 = about 312 billion. Revenue outside the United States (7,073 + 5,218 + 4,194) / 72,229 = 23%. 2026 revenue guidance 72,229 x 1.10 = 79,452. Segments (2025, $ millions): revenue 34,814 + 16,926 + 13,000 + 7,759 = 72,499; less Corporate and Other 270 = 72,229. Shares of segment revenue: USCS 34,814 / 72,499 = 48.0%; CS 23.3%; ICS 17.9%; GMNS 10.7%. Pretax income 6,810 + 3,668 + 1,603 + 3,968 = 16,049; shares USCS 42.4%, CS 22.9%, ICS 10.0%, GMNS 24.7%. Pretax margins: USCS 6,810 / 34,814 = 19.6% (2020 3,103 / 16,347 = 19.0%; 2021 5,958 / 18,922 = 31.5%; 2022 5,400 / 23,914 = 22.6%; 2023 5,433 / 28,116 = 19.3%; 2024 6,377 / 31,427 = 20.3%); CS 3,668 / 16,926 = 21.7% (2020 1,013 / 9,234 = 11.0%); ICS 1,603 / 13,000 = 12.3% (2020 521 / 6,742 = 7.7%; 2021 929 / 7,435 = 12.5%; 2022 578 / 9,061 = 6.4%; 2023 973 / 10,430 = 9.3%; 2024 1,031 / 11,461 = 9.0%); GMNS 3,968 / 7,759 = 51.1% (2020 1,294 / 4,309 = 30.0%; 2021 1,874 / 5,129 = 36.5%; 2022 2,954 / 6,475 = 45.6%; 2023 3,656 / 7,396 = 49.4%). ICS pretax 1,603 / 1,031 - 1 = 55%. GMNS 2024 excluding the Accertify gain 4,398 - 531 = 3,867; 3,968 / 3,867 - 1 = 2.6%. Revenue 2020 to 2025: USCS 34,814 / 16,347 = 2.13; CS 16,926 / 9,234 = 1.83; ICS 13,000 / 6,742 = 1.93; GMNS 7,759 / 4,309 = 1.80. 2020 segment total 16,347 + 9,234 + 6,742 + 4,309 = 36,632; USCS share 16,347 / 36,632 = 44.6%. USCS Q2 2026 pretax 2,065 / 1,676 - 1 = 23%. Regions 2025: pretax 13,054 + 1,255 + 831 + 907 = 16,047; United States 13,054 / 16,047 = 81%; 13,054 / consolidated 13,795 = 95%; outside the United States (1,255 + 831 + 907) / 16,047 = 19%; revenue 56,015 / 72,229 = 78% - card fees, spending, lending, funding, valuation, Delta and per-share arithmetic. — 2013-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in American Express's Forms 10-K, 10-Q, earnings releases and statistical supplements, Delta Air Lines' Form 10-K and market data; operands shown in the source line.
  10. ReportedCard Members in California, Florida, New York, Texas, Georgia and New Jersey account for what the company calls "a significant portion of U.S. consumer and small business billed business and Card Member loans", so even a diversified base of individuals is concentrated in a handful of states.
    American Express Form 10-K for fiscal 2025 - Item 1A risk factors, competition and regulation. — FY2025 · publ. 6 February 2026 · source ↗
  11. ReportedIt rose from about 18% in 2019 to about 26% in 2025; a figure above 30% would mean close to a third of the spending depended on contracts that end.
    American Express Form 10-K for fiscal 2019 - five-year selected financial data (2015-2019), the Delta renewal through 2029 and the three former segments. — FY2019 · publ. February 2020 · source ↗
  12. ReportedIt rose from about 18% in 2019 to about 26% in 2025; a figure above 30% would mean close to a third of the spending depended on contracts that end.
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
Sources
Generated September 28, 2026