Twenty-Six Percent Through PartnersNarrow moat

American Express (AXP) — moat facet

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.

Beyond Delta, American Express depends on a group of partners whose names are on its cards. It lists Delta, Marriott International, British Airways and Hilton Worldwide Holdings as cobrand partners1, and all cobrand portfolios together accounted for about 26% of worldwide billed business in 2025 and about 36% of Card Member loans2.

Cobrand share of Card Member loans (%)38%201937%202040%202136%202236%2025American Express Forms 10-K FY2019-FY2022 and FY2025
Partners carry a larger share of the loans than of the spending.

The billed business share has risen from about 18% in 20193 to 25% in 20244 and 26% in 2025, while the loan share has stayed between about 36% and 40%567. Cobrand cardholders borrow more, relative to their spending, than holders of Amex's own cards.

The agreements are long and costly. Cobrand arrangements run "generally ranging from five to ten years"8, and some oblige Amex to make "a certain level of minimum payments over the life of the agreement"9. When they end, some partners may purchase the loans on their cards, "which could result in the loss of the card accounts and a significant decline in our Card Member loans outstanding"10.

Renewals do happen. Amex signed a multi-year extension of its British Airways cobrand card partnership in the fourth quarter of 202511. But each renewal resets the price, and business development expense, which includes partner payments, rose from $3,762 million in 2021 to $6,457 million in 20251213.

The concentration here is of revenue and of loans, and they differ. Delta is 13% of the spending and 21% of the loans; the other cobrand portfolios together are about another 13% of spending14, and the filings do not split them further.

Losing partners is not hypothetical. Amex's risk factors name the end of the Costco relationship in 2016 and the withdrawal of American Airlines in 2014 from its airport club access programme for Centurion and Platinum cardholders as examples of partner losses15. Both came from partners deciding they could do better elsewhere.

The loan share is the more important number. At about 36% of Card Member loans in 202516, it means more than a third of the interest-earning book sits on cards whose owner could take them elsewhere; a rise above 40% would tie still more of the balance sheet to contracts Amex does not fully control.

Moat trajectory: Narrowing

Cobrand share of billed business 18% (2019) to 26% (2025); loans about 36%.

The number that tests this moat
Reported
Cobrand share of Card Member loans
About 36% (2025)

How much of the loan book could leave with a partner; above 40% would tie more of the balance sheet to contracts Amex does not control.

Source: American Express Form 10-K, FY2025 ↗
References
  1. ReportedIt lists Delta, Marriott International, British Airways and Hilton Worldwide Holdings as cobrand partners, and all cobrand portfolios together accounted for about 26% of worldwide billed business in 2025 and about 36% of Card Member loans.
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  2. ReportedIt lists Delta, Marriott International, British Airways and Hilton Worldwide Holdings as cobrand partners, and all cobrand portfolios together accounted for about 26% of worldwide billed business in 2025 and about 36% of Card Member loans.
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  3. ReportedThe billed business share has risen from about 18% in 2019 to 25% in 2024 and 26% in 2025, while the loan share has stayed between about 36% and 40%.
    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 ↗
  4. ReportedThe billed business share has risen from about 18% in 2019 to 25% in 2024 and 26% in 2025, while the loan share has stayed between about 36% and 40%.
    American Express Form 10-K for fiscal 2024 - revenue lines, the Accertify sale, Delta and cobrand shares, and the small-business sales-practices settlements. — FY2024 · publ. February 2025 · source ↗
  5. ReportedThe billed business share has risen from about 18% in 2019 to 25% in 2024 and 26% in 2025, while the loan share has stayed between about 36% and 40%.
    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 ↗
  6. ReportedThe billed business share has risen from about 18% in 2019 to 25% in 2024 and 26% in 2025, while the loan share has stayed between about 36% and 40%.
    American Express Form 10-K for fiscal 2021 - billed business 2019-2021, average discount rate, net write-off rates, the 2021 reserve release and Delta shares. — FY2021 · publ. February 2022 · source ↗
  7. ReportedThe billed business share has risen from about 18% in 2019 to 25% in 2024 and 26% in 2025, while the loan share has stayed between about 36% and 40%.
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  8. ReportedCobrand arrangements run "generally ranging from five to ten years", and some oblige Amex to make "a certain level of minimum payments over the life of the agreement".
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  9. ReportedCobrand arrangements run "generally ranging from five to ten years", and some oblige Amex to make "a certain level of minimum payments over the life of the agreement".
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  10. ReportedWhen they end, some partners may purchase the loans on their cards, "which could result in the loss of the card accounts and a significant decline in our Card Member loans outstanding".
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  11. ReportedAmex signed a multi-year extension of its British Airways cobrand card partnership in the fourth quarter of 2025.
    American Express fourth-quarter and full-year 2025 earnings release, Form 8-K exhibit 99.1 - 2026 guidance and the dividend increase. — Q4 2025 · publ. 30 January 2026 · source ↗
  12. ReportedBut each renewal resets the price, and business development expense, which includes partner payments, rose from $3,762 million in 2021 to $6,457 million in 2025.
    American Express Form 10-K for fiscal 2023 - income statements for 2021-2023 on the current presentation, segment results for 2022, discount revenue as a share of billed business. — FY2023 · publ. February 2024 · source ↗
  13. ReportedBut each renewal resets the price, and business development expense, which includes partner payments, rose from $3,762 million in 2021 to $6,457 million in 2025.
    American Express Form 10-K for fiscal 2025 - Delta, cobrand partners and partnership concentration. — FY2025 · publ. 6 February 2026 · source ↗
  14. Moat Explorer calcDelta is 13% of the spending and 21% of the loans; the other cobrand portfolios together are about another 13% of spending, and the filings do not split them further.
    Moat Explorer calculation from American Express's reported figures ($ 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.
  15. ReportedAmex's risk factors name the end of the Costco relationship in 2016 and the withdrawal of American Airlines in 2014 from its airport club access programme for Centurion and Platinum cardholders as examples of partner losses.
    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 ↗
  16. ReportedAt about 36% of Card Member loans in 2025, it means more than a third of the interest-earning book sits on cards whose owner could take them elsewhere; a rise above 40% would tie still more of the balance sheet to contracts Amex does not fully control.
    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