Stablecoin and Crypto Card Glossary: 55 Terms Defined

Stablecoin payments borrow vocabulary from two industries that never talked to each other: crypto and card processing. This glossary covers both. Terms are grouped by where you actually meet them, in the order money moves — from your local currency, onto a chain, into a card, and out at a merchant.

The coins themselves

Stablecoin — A crypto token designed to hold a steady price, almost always one US dollar, using reserves or collateral rather than market luck. See Stablecoins 101.

Peg — The price a stablecoin is trying to hold. “Holding the peg” means trading at roughly $1.00.

Depeg — When a coin trades meaningfully away from its peg. A few tenths of a cent for an hour is noise; several cents for days is a warning. See anatomy of a depeg.

Reserves — The assets an issuer holds to back the coins it has issued: bank deposits, short-term government debt, and sometimes riskier things. The quality of the reserves is the quality of the coin.

Attestation — An accounting firm’s report confirming what an issuer held on a given date. It is a snapshot, not a full audit: it checks that the assets existed, not that the business is sound.

Audit — A broader examination of financial statements over a period. Most stablecoin issuers publish attestations rather than full audits, which is why the distinction gets argued about.

Mint / Redeem — Creating new coins by sending dollars to the issuer (mint) and destroying them by returning coins for dollars (redeem). This is the mechanism that anchors the peg.

Authorized participant — A vetted institutional client with a direct mint-and-redeem account at the issuer. Retail users almost never redeem directly; they sell on an exchange and let these firms do the arbitrage.

Blacklist / Freeze — Centralized issuers can make specific addresses unable to move their coins, usually on a law-enforcement request. Fiat-backed coins have this; it is a feature for recovering stolen funds and a risk if you are wrongly caught.

Fiat-backed / crypto-collateralized / synthetic — The three live designs for holding a peg: dollars in a bank, over-collateralized crypto locked in a contract, or a hedged trading position. Each fails in a different way.

Chains, wallets and transfers

Blockchain / Chain / Network — The shared ledger a token lives on. The same brand of coin exists separately on several chains, and those copies are not interchangeable without a bridge or an exchange.

Block — A batch of transactions written to the ledger at once. Chains produce blocks on a rhythm — seconds on most chains people use for stablecoins, about ten minutes on Bitcoin.

Gas — The fee paid to the network to process your transaction. It is denominated in the chain’s own token: ETH on Ethereum, TRX on Tron, SOL on Solana. You need a small amount of that native token to move any other token, which surprises people who hold only USDT.

Confirmation — One block built on top of the block containing your transaction. More confirmations means more work would have to be undone to reverse it.

Finality — The point where a transaction is considered irreversible by the chain’s own rules. Different from “confirmed enough for your exchange,” which is a business policy set higher or lower than the technical threshold.

Address — The destination string for a transfer. Formats differ by chain and are a useful sanity check: Ethereum-style addresses start with 0x and are 42 characters, Tron addresses start with T and are 34.

Memo / Destination tag — An extra reference some exchanges require alongside the address so they can credit the right customer. Omitting a required memo is one of the most common ways deposits go missing.

Bridge — A service that moves value between chains by locking tokens on one side and issuing a claim on the other. Bridges have been the single largest category of crypto theft, so prefer routing through an exchange when you can.

Wrapped token — A token on one chain that represents an asset held on another. Convenient, but you are now trusting whoever holds the original.

Layer 2 (L2) — A network that batches transactions and posts compressed proofs back to a main chain, inheriting much of its security at a fraction of the fee. Arbitrum, Optimism and Base are the common ones for Ethereum.

Self-custody vs custodial — Holding your own keys versus letting a company hold funds for you. A crypto card balance is custodial by definition — that is the trade you make for spendability.

Seed phrase — The 12 or 24 words that regenerate a self-custody wallet. Anyone who has them owns the funds. No legitimate service will ever ask for them.

Block explorer — A website that lets you look up any transaction or address on a chain. When a transfer “hasn’t arrived,” the explorer is the first place to check whether it actually left.

Getting in and out of local currency

On-ramp / Off-ramp — Converting local currency into stablecoins (on) or back out (off): exchanges, card top-ups, brokers, peer-to-peer markets. In practice the off-ramp is where most of the cost and most of the friction live.

P2P trading — Buying or selling stablecoins directly with another person through an exchange’s escrow. Common where card purchases of crypto are blocked; requires care about counterparty ratings and about receiving funds from unknown bank accounts.

Spread — The gap between the price you can buy at and the price you can sell at. Services advertising “zero fees” usually earn here instead, so compare the final amount received rather than the fee line.

Slippage — The difference between the price you were quoted and the price you got, caused by the market moving or your order being large relative to available liquidity.

KYT (Know Your Transaction) — Blockchain analytics that score incoming funds for links to sanctioned or stolen sources. This is why a deposit from an unknown P2P counterparty can get your exchange account frozen even though you did nothing wrong.

Cards and payment rails

Issuer — The regulated institution that holds your balance or credit line and approves or declines each transaction. On a crypto card this is a licensed bank or e-money firm, not the crypto brand on the card.

Acquirer — The merchant’s bank or processor, which submits transactions into the card network on the merchant’s behalf.

Program manager — The company that runs the technical and compliance stack for a card program on an issuer’s licence. Most crypto cards are a brand plus a program manager plus a licensed issuer.

BIN (Bank Identification Number) — The leading digits of a card number that identify the issuing program. Historically six digits, now eight on Visa and Mastercard. Merchants and fraud systems use it to classify your card, which is why some sites reject an entire card program at checkout.

MCC (Merchant Category Code) — A four-digit code describing what the merchant sells, standardised as ISO 18245. Issuers approve or decline partly by MCC, which is why a card can work at a supermarket and refuse the same amount at a betting site.

Quasi-cash — Purchases that behave like obtaining cash rather than buying goods, including buying crypto. It is not a single merchant category: it is flagged by indicators sent alongside the MCC in the authorization. Visa’s rules actually require merchants to process quasi-cash as a purchase, so when your bank prices a crypto buy like a cash advance, that is your issuer’s choice under your cardholder agreement, not a network requirement.

Authorization — The real-time approve-or-decline decision, and the hold it places on your balance. Explained in full in how card authorization works.

Hold / Pre-authorization — A temporary reservation of funds for an amount the merchant does not know yet: a fuel pump, a hotel, a car rental. The final charge replaces it later, but the hold can shadow your balance for days.

Clearing — The stage after authorization where the merchant submits the real final amount. This is when a $1 fuel authorization becomes your actual $43 fill-up.

Settlement — The stage where money genuinely moves between the acquirer and the issuer through the network’s settlement banks, typically a day or more after you tapped.

Interchange — The fee the merchant’s bank pays your card’s issuer on every purchase. You never see it, but it funds most card rewards and shapes which cards exist. See interchange explained.

Scheme fees — What Visa and Mastercard charge the banks on both sides for running the network. Separate from interchange, and much smaller.

3-D Secure (3DS) — The extra verification layer on online payments, branded Visa Secure and Mastercard Identity Check. Most checkouts now pass through it invisibly using device and behaviour signals; you only see a code prompt when the risk engine wants proof. See 3DS and SCA explained.

Tokenization — Replacing your real card number with a device-specific substitute, which is what happens when you add a card to a phone wallet. The merchant never sees the underlying number.

Stand-in processing — When the network answers on the issuer’s behalf because the issuer’s systems are unreachable, using pre-agreed limits. It keeps cards working during outages and occasionally approves things your real balance would not.

Chargeback — The card-network dispute process that can pull a payment back from the merchant. Strictly, the right belongs to your issuer, not to you; consumer law is what obliges the issuer to act on your behalf. There is no on-chain equivalent — an executed blockchain transfer is final — which is a real reason to pay by card rather than by wallet transfer.

Foreign transaction fee — A percentage your issuer adds when you pay in a currency other than your card’s base currency. Separate from, and stacked on top of, the exchange rate used.

DCC (Dynamic Currency Conversion) — The terminal offering to charge you in your home currency instead of the local one. It is almost always a worse rate than letting your card convert. Always choose the local currency. See FX and DCC traps.

E-money — A regulated category of stored value issued against funds received, which is what most non-bank card balances legally are. It usually comes with safeguarding rules rather than deposit insurance. See prepaid and e-money.

Safeguarding — The requirement that an e-money firm hold customer funds separately from its own, so they are not part of the estate if the firm fails. Weaker and slower than deposit insurance, but not nothing.

Rules and compliance

KYC (Know Your Customer) — Identity verification: document, selfie, proof of address. Every regulated card provider requires it, and higher tiers unlock higher limits.

AML (Anti-Money-Laundering) — The wider set of controls firms must run: transaction monitoring, sanctions screening, suspicious activity reporting. It is why accounts get frozen without an explanation you find satisfying.

Residency vs location — Almost every restriction in this space keys off the address on your KYC file, not where your phone is. A VPN does not change which products you may use, and using one against the terms is a good way to lose an account.

EMT / ART — The two stablecoin categories under EU law. An e-money token references one official currency; an asset-referenced token references a basket, a commodity, or anything else.

MiCA — The European Union’s Markets in Crypto-Assets regulation, the rulebook behind European exchanges restricting some stablecoins. See regulations.

GENIUS Act — The US federal law creating a licensing and reserve regime for payment stablecoin issuers. Signed in July 2025, but its requirements only take effect in January 2027 absent earlier final rules — it is law, not yet an operating regime. See regulations.

Payment stablecoin — The regulatory term of art for a coin used for payments and redeemable at par, as distinct from yield-bearing tokens and tokenized funds, which are regulated as investments instead.

Missing a term? The glossary grows as the blog covers new ground. For the fuller treatment of any entry here, follow the link on the term.