# Crypto payments glossary: plain-English definitions

> Short, plain definitions of the terms merchants meet when accepting crypto payments: payment gateways, invoices, payment links, hosted checkout, networks, stablecoins, confirmations, gas fees, sweeps, underpayments, custody, webhooks and more.

Source: https://quantumines.com/crypto-payments-glossary
Published: 2026-11-08 · Last updated: 2026-11-08
Publisher: Quantumines (https://quantumines.com/), founded by Muhammad Ali Raza (Ali Arbi)

Crypto payment gateways use a lot of jargon. This glossary explains each common term in a sentence or two, so you can compare gateways and set up payments without surprises. It is written by Quantumines, which also runs the crypto payment gateway CryptoMerchant; the definitions apply to any provider.

## The basics

Crypto payment gateway
A service that lets a business accept cryptocurrency: it shows the customer where and how much to pay, watches the blockchain, and tells the business when the payment has arrived.
Invoice
A request for one payment of a set amount. In crypto it usually has its own deposit address, a locked exchange rate and an expiry time.
Payment link
A web link that opens a payment page for a fixed price or an amount the customer enters. It can be shared in a message, an email or a social profile, with no code.
Hosted checkout
A payment page run by the gateway that a shop sends customers to at checkout. The gateway handles the crypto part and sends the customer back when done.
API
A programming interface that lets a website or app create invoices and check payments automatically.
Webhook
A message the gateway sends to the merchant's server when something happens, such as an invoice being paid. Good gateways sign webhooks so the merchant can check they are genuine.

## Coins and networks

Coin or token
The asset being paid, such as Bitcoin (BTC), Ether (ETH) or USDT. A token is an asset that runs on another blockchain, as USDT does on Tron or Ethereum.
Network (chain)
The blockchain a payment travels on. The same token can exist on several networks, and a payment sent on one network does not arrive on another.
Stablecoin
A token designed to keep a steady value, usually one US dollar, such as USDT or USDC. Merchants often prefer them because the price does not swing during checkout.
EVM network
A blockchain compatible with Ethereum, such as BNB Smart Chain, Polygon, Base or Arbitrum One. The same address format works across them.
Wrong-network payment
A payment sent on a network the invoice did not ask for. Depending on the gateway, it may be recoverable, delayed or lost, so checkouts should show the network next to the address.

## Amounts, fees and timing

Locked exchange rate
The crypto amount fixed for an invoice for a set time, so a price in dollars converts to a known amount of crypto.
Invoice expiry
The time after which an unpaid invoice closes and its rate is no longer guaranteed.
Confirmation
A block added after the one containing the payment. Gateways wait for a number of confirmations before treating a payment as final.
Gas fee (network fee)
The fee paid to the blockchain to process a transaction. It varies by network and can be higher than the gateway's own fee on busy networks.
Processing fee
The gateway's own charge, often a percentage of each paid invoice.
Underpayment
A payment that arrives short, often because the customer's wallet subtracted its fee. Gateways handle this with a tolerance, a top-up request or a refund.
Overpayment
A payment that arrives above the invoice amount. Gateways differ on whether the extra is refunded, credited or held for the customer.
Sweep
Moving funds from an invoice's deposit address into the merchant's main wallet. It costs a network fee.
Payout (withdrawal)
Sending the merchant's balance to a wallet or exchange account they control. Gateways may set minimums, schedules or fees.
Conversion
Turning received crypto into another coin, a stablecoin or local money. Some gateways do this automatically, usually for a fee.

## Custody and compliance

Custodial gateway
The gateway holds the keys to the wallets that receive payments and pays out on request. Simpler to use; you rely on the gateway's security.
Non-custodial gateway
Payments go straight to wallets the merchant controls. More control; the merchant is responsible for keeping keys safe.
KYC / KYB
"Know your customer" and "know your business": identity checks some gateways or laws require before an account can be used.
Self-hosted processor
Payment software the merchant runs on their own server, such as BTCPay Server, instead of using a hosted gateway.

Rules on accepting and reporting crypto income differ by country; this glossary is not legal or tax advice.

## Where to go next

- How can I accept USDT payments on my website without writing code? (https://quantumines.com/answers/accept-usdt-payments-without-code)
- How much do crypto payment gateways charge? (https://quantumines.com/blog/crypto-payment-gateway-fees-explained)
- CryptoMerchant (https://cryptomerchant.online): accept crypto payments with invoices, payment links, hosted checkout and an API (built by Quantumines)
- Proxy glossary (https://quantumines.com/proxy-glossary) and Quantumines facts (https://quantumines.com/facts)