You probably opened a Delta SkyMiles credit card for the sign-up bonus. Maybe you liked the idea of free checked bags or priority boarding. You swipe it at the grocery store, at the gas pump, at restaurants.

Every time you do, Delta Air Lines collects, not from you directly, but from the bank that issued your card. A new investigation into airline financial filings reveals just how much those everyday swipes are worth, Reuters reported.

The numbers are staggering, and they should reshape how you think about loyalty programs, reward miles, and the true cost of flying.

The biggest beneficiary? Delta. The funds it collected from a single credit card partner in 2025 dwarfed what most airlines generate from selling plane tickets.

Delta Air Lines collected $8.2 billion from American Express in a single year

Delta received $8.2 billion in cash from American Express in 2025, Reuters reports.

That represented roughly 14% of the airline’s adjusted operating revenue and was about 1.4 times its adjusted operating income.

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The $8.2 billion marked an 11% jump over what American Express paid Delta in 2024. Delta’s full-year 2025 results show the airline posted $63.4 billion in operating revenue and $5.8 billion in operating income, per its SEC filings.

Credit-card income did not just contribute. It anchored the bottom line.

How the money actually flows to Delta

A Delta spokesperson told Reuters that part of the $8.2 billion is booked as revenue immediately. The remainder gets deferred until you redeem your SkyMiles.

When you let miles sit unused in your account, Delta books the cash today and carries the redemption obligation later.

That structure gives the airline a powerful financial cushion. Credit-card revenue does not fluctuate with jet fuel prices or seasonal travel demand.

Every major U.S. airline now depends on credit-card revenue

Delta’s $8.2 billion is the headline, but every major domestic carrier has restructured its business model around co-branded credit-card income. American Airlines reported $6.2 billion in 2025 cash payments from co-brand and other partners, according to the Reuters review.

That was roughly four times America’s adjusted operating income. The carrier expects its new co-brand agreement with Citi to help close its profitability gap with Delta and United.

Alaska Airlines sees loyalty revenue as a stabilizer

At Alaska Airlines, loyalty revenue made up about 16% of total revenue in 2025. CFO Shane Tackett told Reuters the co-brand partnership stabilizes results through demand swings.

Southwest Airlines sells most of its points to JPMorgan Chase. Delta says nearly all of its marketing-agreement cash comes from American Express. The dependency runs deep across the entire industry.

Airlines are rewriting loyalty rules to favor credit card spending over flying

If you fly without an airline credit card, you are already losing ground. The major carriers are rapidly shifting reward structures to favor card spending over actual seat purchases.

United Airlines slashes non-cardholder earning rates in April 2026

Starting April 2, 2026, United Airlines members without its co-branded card will earn just 3 miles per dollar spent on eligible flights, Reuters reports.

Cardholders earn at least 6 miles. United now also requires a qualifying credit card to earn any miles on basic economy tickets.

Delta Air Lines received $8.2 billion in cash from American Express in 2025.

Alvin Man/Getty Images

American Airlines stopped rewarding basic economy passengers

American Airlines has eliminated AAdvantage miles and Loyalty Points on basic economy tickets. If you book the cheapest fare without the card, you earn nothing toward status or future flights.

Delta takes a slightly different path but reaches the same destination. It lets you count spending on co-branded American Express cards toward elite status qualification. The message from all three carriers is clear: Get the card or get left behind.

Your miles are losing value faster than you realize

Here is the uncomfortable reality about airline rewards in 2026: The purchasing power of your miles keeps declining while the airlines keep collecting more from the banks that issue your card.

Dynamic pricing has changed the redemption math

Delta pioneered dynamic award pricing. That means the number of miles you need for a flight fluctuates based on demand. A Bloomberg analysis found that Delta’s points-to-dollars ratio now resembles a cashback program rather than a premium loyalty tool.

The system is not particularly favorable for most consumers, Yi Gao, associate professor of aviation management at Purdue University, told Bloomberg. For business travelers flying premium cabins, the card still delivers value. For everyday cardholders swiping at the grocery store, the math is getting harder to justify.

The hidden cost of chasing airline rewards

If you carry a balance on an airline credit card, you are almost certainly losing money. Average credit card APRs remain near 24%, per LendingTree data. No sign-up bonus or free checked bag offsets that kind of interest.

Ask yourself these questions before committing to any airline card.

• Do you pay your balance in full every month? If not, a no-annual-fee cashback card is the smarter choice.
• Do you fly this airline at least four to six times per year? Occasional flyers rarely earn enough for meaningful redemptions.
• Does the annual fee still make sense against the perks you actually use? A $550 card is a waste if you only use the free checked bag benefit.
• Are you redeeming miles within 12 months? Points that sit in your account can be devalued by the airline at any time.

Federal regulators are watching airline-bank partnerships closely

The U.S. Department of Transportation asked American, Delta, Southwest, and United in 2024 for detailed information about their rewards programs and policies, Reuters reports.

All four carriers responded. Their submissions remain under review.

Consumer advocates want stronger disclosure requirements

John Breyault, vice president of public policy at the National Consumers League, told Reuters that airlines can change earning and redemption values without giving customers clear advance notice. He argued that stronger transparency rules are needed.

Some credit-card issuers may be deflating the value of points already earned, the Consumer Financial Protection Bureau said in late 2024. That finding could reshape how airlines and banks negotiate future partnership agreements.

On Capitol Hill, Senators Dick Durbin and Roger Marshall have pushed for the Credit Card Competition Act. Airlines argue the legislation would threaten rewards programs entirely. Airlines for America estimates roughly 30 million U.S. households hold at least one airline credit card.

Delta is targeting $10 billion a year from its American Express deal

Delta is not pulling back. The airline has publicly stated its long-term goal of reaching $10 billion in annual revenue from the American Express partnership. That would be a 22% increase over the 2025 figure.

What that growth trajectory signals for Delta SkyMiles members

Delta Air Lines CEO Ed Bastian credited the loyalty ecosystem during the Q4 2025 earnings call, per the carrier’s earnings release. Premium revenue grew 7% year over year. New card acquisitions are skewing younger, with millennial and Gen Z members now making up nearly 50% of the active SkyMiles base.

For you, the trajectory raises a direct question. As Delta chases $10 billion, will it keep tightening the rules for how you earn and redeem miles? Recent history suggests yes. The airline already moved to dynamic pricing and restricted lounge access for lower-tier cardholders.

How to protect yourself in the new loyalty economy

You do not have to stop using airline credit cards. But you do need to treat them like any financial product, not a perk.

• Audit your card every 12 months.
• Check whether your annual fee still justifies the benefits you actually redeem.
• Compare your earning rate against flat-rate 2% cashback alternatives.
• Track whether your miles are appreciating or losing purchasing power over time.

Airlines can change redemption values at any time, without warning. If you have a meaningful points balance, use it within the next year. Holding miles is not the same as holding savings. There is no FDIC insurance and no guaranteed value.

Watch for points-devaluation announcements closely

Airlines typically disclose loyalty program changes 60 to 90 days before they take effect. When those announcements come, act quickly. Redeem your points before the new structure kicks in.

The bottom line is straightforward. Airlines have figured out that your credit card swipe is more valuable than your plane ticket. That shift is not going to reverse.

Your best move is to treat rewards like any other financial product. Read the fine print, run the numbers, and never assume the deal stays the same.

Related: American Airlines adding perk some travelers will love

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