How a crypto card works
The cardholder holds crypto-assets, often stablecoins, in a wallet that the card app controls or is connected to. The conversion to fiat currency happens in one of two ways:
- Pre-funded: the cardholder sells crypto into a fiat card balance, and the card spends that balance
- Just in time: at authorisation the app prices the purchase in crypto, sells that amount and funds the payment within seconds
What the card schemes require of a crypto card
Under the Visa Core Rules of 18 April 2026 (1.4.4.6), non-fiat funds are converted to a fiat currency before deposit into the account linked to a Visa card, and the issuer needs Visa's approval before launching such a programme.
The Mastercard Rules of 2 June 2026 (3.18) require conversion to a currency Mastercard recognises before funds are deposited to a card. They also require Mastercard's prior written consent for activity that involves cryptocurrency, and for marketing that links a card to it.
The parties behind a crypto card
A crypto card joins two regulated activities. The card side needs a licensed issuer, usually a BIN sponsor, and a processor. On the crypto side, MiCA lists custody of crypto-assets and their exchange for funds as crypto-asset services, which in the EU require authorisation (Articles 3 and 59).
The app's ledger holds both sides: a crypto balance, a fiat card balance, the rate and the fee of each conversion, and refunds, which come back in fiat days after the crypto was sold.
Crypto card or stablecoin payment?
- Stablecoin payment
- The merchant, or its payment provider, receives the stablecoin itself over a blockchain. With a crypto card the merchant is paid in fiat currency through the card scheme.
- Crypto-backed credit card
- Lends fiat currency against crypto-assets held as collateral, where a crypto debit card sells them.
Where a crypto card shows up in a platform
Modules that do the work
- Card issuingVirtual and physical cards, wallets and controls, on the issuer processor you choose.
- Custody & walletsWallets on every major chain, with MPC custody from leading providers or your own keys.
- FXCurrency conversion with live rates, your margins and the liquidity provider you choose.
- LedgerThe double-entry book of record behind every balance, fee and transfer.
Platforms that need it
Guides that go deeper
- How to build a crypto card app like RedotPayHow a stablecoin card really works: what happens between the tap and the answer, how the crypto is converted and held, what each module does, and the licences on each side.
- White-label crypto banking: the software, the two licences and who holds whatHow a crypto banking app works: an IBAN account, crypto wallets, conversion and a card, the two licences behind them, who holds the money and the coins, and SaaS, API or source code.
- BIN sponsorship: how to launch a card programmeWho does what in a sponsored card programme, what the BIN sponsor, Visa and Mastercard ask of a programme manager, the rules for crypto-linked cards, and where an EMI licence fits.
Where it is written
The laws and standards this page's facts come from.
- Visa Core Rules and Visa Product and Service Rules, 18 April 2026: 1.4.4.6, Cardholder Account Currency (Visa)
- Mastercard Rules, 2 June 2026: Rule 3.18, Recognized Currencies (Mastercard)
- Regulation (EU) 2023/1114, MiCA, Articles 3 and 59 (EUR-Lex)
General information, not legal advice: what applies to you depends on your services and your market.