5 Architectural Models for Stablecoin-linked Card Programs
Why this matters
Stablecoins are entering the mainstream, with over $300B1 in circulation and regulatory clarity driving an inflection point for adoption. The next challenge is less about access and more about utility at scale. Mainstream adoption relies on meeting users where they are. Stablecoin-linked cards succeed by wrapping digital assets in familiar safety nets of the card networks: consumer protections, dispute resolution, and global reach. Users want to spend stablecoins with the cards they already have in their wallets and anywhere Visa and Mastercard are accepted.
Stablecoin-linked card programs at the center of this conversation. But here's what most people building in this space haven't internalized yet:
The entire architecture of a stablecoin-linked card program – its costs, capital efficiency, regulatory posture, and user experience—hinges on a single decision: when, or whether, stablecoins are converted to fiat.
Conversion is the architectural fork in the road. This single decision affects everything from liquidity management, reserve sizing and regulatory obligations. Everything else in a card program model follows from that inflection point.
Below are five distinct stablecoin card models we see in the market today.
Model 1: Prefunded in fiat, all stablecoin converted before user transacts
How it works
Users have stablecoins in a wallet managed by the card program. The program manager converts stablecoins to fiat and prefunds a card account with fiat. The user spends from a fiat balance.
Why teams choose it
- Generally understood by banks, networks, and regulators
What you give up
- Money movement is typically constrained by traditional bank operating hours
- Fiat reserves must be sized to cover weekend and holiday gaps in settlement cycles
Best for
Program managers who can’t or don’t want to hold stablecoin but still want to offer users the flexibility of both fiat and stablecoin funding.
Model 2: Real-time conversion at point of sale
How it works
Stablecoins stay in a user’s wallet until he or she swipes. Conversion from stablecoin to fiat happens in real time during card authorization.
Why teams choose it
- Clean UX with a single balance
- Users retain funds in stablecoin and the ability to move funds 24/7, until the moment of spend
- Limited changes to downstream settlement infrastructure
What you give up
- Fiat reserves must be sized to cover weekend and holiday gaps in settlement cycles
- No real improvement in network settlement efficiency or reserve requirements
- Operations must accommodate stablecoin movement, without unlocking its full capital efficiency
Best for
Products that want better UX without redesigning network settlement; crypto programs where onchain balances are core to the product
Model 3: Settle to the network in stablecoin
How it works
Stablecoins are not converted to fiat at any point in the settlement flow. Cardholder purchases settle directly to the sponsor bank and card networks seven days a week.
Why teams choose it
- Capital efficiency: programs settle every day, so there’s less idle capital; reduced or eliminated weekend and holiday prefunding
- Simpler treasury operations: no need to convert stablecoin to fiat
What you give up
- Fewer sponsor banks support this today
- Requires mature stablecoin treasury, operations, risk, and compliance capabilities
Best for
Programs with established stablecoin treasury operations; crypto-native issuers optimizing for reserve efficiency; programs building for long-term stablecoin-first infrastructure.
Model 4: Self-custodial (emerging)
How it works
A user retains self-custody of his or her stablecoins in a self-hosted wallet. Card transactions trigger onchain authorization logic via smart contracts or signed transactions.
Why teams are excited
- Full self-custody lets users keep flexibility and control right up to the moment they spend
- Clear separation between a user’s funds and settlement funds
- Program flexibility: reach more users who want to spend from an existing wallet
Why teams hesitate
- Smart contract and signing risk
- Requires a new authorization flow (including failure and dispute handling)
- No production-scale programs in the market today
Model 5: Stablecoin-backed corporate / B2B programs
How it works
A company holds stablecoins at the treasury level. Card programs draw against that balance for employee spend, vendor payments, or operational expenses.
Why teams choose it
- Programmable spend controls (spending caps, recurring vendor payments)
- Near-instant reconciliation
What to watch
- Requires operational change to accounting and finance systems
Best for
Distributed teams, global businesses, and Web3-native companies
Bottom line
Teams might start with Model 1 because it’s a fairly speedy upgrade to existing fiat infrastructure.
The real unlock is Model 3, where stablecoins aren’t just a funding source, but a settlement asset. Getting there depends less on smart contracts and more on sponsor banks, networks, and regulatory readiness.
Your architecture choice should consider:
- Who your users are
- How much capital you’re willing to lock up
- And how far down the infrastructure stack you’re prepared to go
We don't say this lightly: most banks aren't equipped to be the infrastructure partner for a stablecoin card program. The technical complexity, regulatory fluency, and specialized risk management require capabilities that extend beyond traditional card sponsorship.
