How Stablecoin Cards Work: The 7-Layer Infrastructure

Seven layers behind a stablecoin card

#	Layer	What it does	Example providers
01	Card issuing	Holds the Visa or Mastercard license, issues the card numbers (BINs) and settles with the network.	Rain, Reap, Monavate, Wirex, Lead Bank via Stripe Issuing
02	Card processing	Approves or declines each payment in real time, places holds and handles clearing.	Marqeta, Lithic, Thredd, Highnote, i2c
03	Pay-ins and payouts	Turns fiat into stablecoins and back, and pays out to wallets or bank accounts.	BVNK, Bridge, Conduit, zerohash, MoonPay, Transak
04	Fiat accounts and rails	Provides IBANs and virtual accounts and connects to ACH, SEPA and wires.	Banking Circle, OpenPayd, Nium, Clear Junction
05	Balances and ledger	Tracks who owns what, on-chain or in an internal ledger.	Modern Treasury, Formance, or the blockchain itself (Solana, Plasma)
06	Wallets and custody	Holds the stablecoins, either for the user (custodial) or in a wallet the user controls.	Fireblocks, BitGo, DFNS, Privy
07	Risk and compliance	Identity checks, fraud screening and blockchain analytics.	Sumsub, Persona, Veriff, Sardine, TRM Labs

Examples are illustrative, not exhaustive or ranked.

Prefunded vs self-custody: two different machines

Both models feel identical at the checkout, but they ask very different things of the stack.

Prefunded (custodial): you load stablecoins into the provider's account first. The card works like a prepaid card against an internal ledger, so authorization is fast and simple. The trade-off is that the provider holds your money.
Self-custody: funds stay in your wallet until you pay. The issuer has to check and pull the exact amount on-chain within the few seconds Visa or Mastercard allows, which needs smart-contract wallets with spending allowances. You keep control, and the provider never pools your funds.

In our ranking of the best stablecoin cards, KAST, RedotPay and Coinbase Card are prefunded; MetaMask Card, Plasma One, Wirex One and ether.fi Cash are self-custodial.

Full-stack providers are winning

Stitching seven vendors together takes time and licenses. That is why a few companies now bundle the whole stack in one integration: Rain and Reap hold Visa principal membership themselves; Bridge combines Stripe Issuing with stablecoin conversion and wallets; and Mastercard now sells stablecoin-linked cards and accounts through BVNK. Rain, for example, let Western Union launch its Stablecard in 37 markets at once.

The stack behind popular stablecoin cards

Card	Model	Issued by
KAST	Prefunded balance (custodial)	Rain, on Visa
Western Union Stablecard	Prefunded balance	Rain, on Visa
Plasma One	Self-custody wallet	Rain, on Visa; accounts by Bridge
MetaMask Card	Self-custody wallet	Monavate (issuer) and Baanx (provider), on Mastercard
Coinbase Card	Prefunded balance (custodial)	Pathward, on Visa
Gate Card (Gate US)	Prefunded balance	Lead Bank on Visa, via Bridge and Stripe Issuing

Per issuer disclosures and card terms, November 2026.

Why it matters when you choose a card

Custody decides who holds your money if something goes wrong.

The issuer and its license decide where a card is available and how quickly a program can expand.

The conversion layer decides the real cost: the spread between your stablecoin and the merchant's currency.

The market these layers serve is growing fast: quarterly stablecoin card spend went from $38 million at the end of 2023 to $3.3 billion in the third quarter of 2026. For the coins behind the cards, see the list of stablecoins.

Stablecoin card infrastructure, answered

How do stablecoin cards work?

When you pay, the card network asks the issuer to approve the payment in the merchant's currency. The issuer checks your stablecoin balance or wallet, converts the amount from USDC or USDT, and settles with the merchant in fiat. Several companies handle this behind the scenes: an issuer, a processor, a conversion provider, a custodian and compliance tools.

What is the difference between a self-custody and a prefunded stablecoin card?

A prefunded (custodial) card spends a balance you have already loaded into the provider's account, like KAST or Coinbase Card. A self-custody card pulls funds from a wallet you control at the moment of payment, like MetaMask Card or Plasma One. The second needs real-time on-chain authorization; the first works like a normal prepaid card.

Who issues stablecoin cards?

Most consumer stablecoin cards are issued by specialists rather than banks. Rain and Reap are Visa principal members that issue cards directly; others work through sponsor banks such as Lead Bank or Pathward, or e-money issuers such as Monavate. Bridge issues cards through Stripe Issuing, and Mastercard offers stablecoin-linked cards through BVNK.

How do companies launch a stablecoin card?

Usually by partnering with a full-stack provider such as Rain, Reap or Bridge with Stripe Issuing, which bundle issuing, processing, conversion and compliance in one integration. Gate US says it launched its card with Bridge and Stripe in about six months, half the time its bank partner had estimated.

Sources: Rain, Bridge, BVNK and Mastercard announcements (2026); MetaMask and Coinbase help centers; Gate US case study (Bridge, 2026); card spend data compiled by Adil Ashfaq. Provider lists draw on industry maps including Neobankster's "Anatomy of a Crypto Neobank".

How Stablecoin Cards Work