You tap your crypto card for a $100 coffee. Two seconds later, a push notification says the USDC equivalent was deducted. The barista nods. You assume $100 left your wallet and landed in the shop’s account.
Not quite. The merchant probably received about $98.20. The other $1.80 was sliced up by players you never saw — and the biggest slice went to your issuer.
That invisible split is the four-party model, and it shapes every purchase you make with a crypto-linked card.
The five roles on stage
A standard Visa or Mastercard transaction has five actors:
- You (cardholder) — the person tapping.
- Merchant — the shop.
- Acquirer — the bank or payment firm that signed the merchant, supplied the terminal, and settles the money.
- Issuer — the bank that gave you the card, holds your balance or credit line, and authorizes the payment.
- Card scheme / network — Visa or Mastercard. It sets the rules, routes messages, and clears funds between acquirer and issuer.
The “four-party” name counts you, merchant, acquirer, and issuer. The network sits in the middle as the rails. The acquirer is not the network: the terminal’s brand is usually the acquirer; the Visa/Mastercard logo is the rail.
The alternative is the three-party (closed-loop) model, where one company issues cards and signs merchants directly — think American Express or many store cards. The four-party model wins because thousands of banks and merchants plug into one open network, so your card works almost everywhere.
How the $100 coffee gets split
When you tap, the terminal asks your issuer to approve the $100. That step only holds the money; settlement happens later in a batch. See inside card authorization for what happens in those moments.
At settlement, the merchant’s MDR (Merchant Discount Rate) is applied. Say it is 1.8%:
$100 − $100 × 1.8% = $98.20
The missing $1.80 is divided roughly like this:
- Interchange fee — acquirer pays issuer. At 1.2%, that’s $1.20. The biggest slice flows to the bank that issued your card.
- Scheme fee — both acquirer and issuer pay the network a toll for clearing and security. Maybe $0.15.
- Acquirer margin — what’s left, about $0.45, is the acquirer’s gross revenue before costs.
So the acquirer — the one handling the terminal and deposits — keeps the smallest piece. The issuer, which seems invisible at the point of sale, takes the biggest piece.
Why? The issuer carries the heavy lifting: it holds your balance or credit line, manages fraud risk, runs customer service, and pays for cashback or lounge perks. Interchange is how the merchant side subsidizes those costs. Want to test the numbers? Try our fee calculator.
What this means for crypto-card users
If you pay with a crypto card — a Visa or Mastercard backed by USDT, USDC, or BTC — the four-party model still applies. The merchant still pays MDR, the issuer still collects interchange, and the network still takes its scheme fee. Your stablecoin top-up only changes how you fund the card; it does not change how the merchant side splits the fee stack.
A crypto card with generous cashback is likely funded, in part, by the interchange the issuer earns every time you tap. If you’re choosing between cards, our card comparison tool can help you weigh rewards against foreign-transaction fees and top-up costs.
If you top up with stablecoins, you may also care about network fees, conversion spreads, and whether the issuer converts your USDC to fiat before authorization. See how to top up a crypto card with USDT and use the stablecoin converter to check rates.
Cross-border: where crypto cards can save (or cost) you
Use the same card abroad and the chain gets longer.
- Cross-border interchange — when your issuer and the merchant’s acquirer are in different regions, a higher interchange table often applies. More risk and dispute complexity mean a bigger cut.
- Currency conversion — the foreign amount must become your billing currency. The markup can come from:
- the scheme’s wholesale conversion rate plus a small scheme fee,
- your issuer’s foreign-transaction fee (often 1–3%),
- or DCC (Dynamic Currency Conversion), the checkout prompt asking “pay in USD or EUR?” Choosing your home currency at the point of sale usually gives a worse rate. The rule: choose local currency and let the scheme handle conversion.
Many crypto cards market themselves as travel-friendly because they convert stablecoins to fiat at rates closer to wholesale, or because they skip some issuer-side FX fees. Knowing which layer adds the markup tells you whether the saving is real.
Regulation and rewards
Interchange is a prime regulatory target. When regulators cap it, issuers lose revenue and often respond by cutting rewards or adding annual fees.
Notable examples:
- The EU caps consumer-card interchange at 0.2% for debit and 0.3% for credit.
- The US Durbin Amendment limits debit interchange for large banks.
- Australia and other markets have their own caps.
So the rewards you earn on a crypto card partly reflect what interchange the issuer is allowed to collect in your region. Lower caps can mean lower cashback — regardless of how the card is funded.
Bottom line
- The four-party model means you, merchant, acquirer, issuer, with the network in the middle.
- The merchant’s MDR is split into interchange (to issuer, the big slice), scheme fee (to network), and acquirer margin (the small slice).
- If you use a crypto card, the same split happens. Your stablecoin top-up changes your funding cost, not the merchant fee stack.
- Cross-border fees and DCC can add hidden costs; paying in local currency is usually cheapest.
- Regulatory caps on interchange shape the rewards and fees you see.
The next time a card promises “zero merchant fees,” remember: someone still takes a cut. The question is who, and whether the cut comes back to you as rewards, travel perks, or lower FX costs.