What are USDC and USDT, and why accept them?

USDC and USDT are stablecoins, tokens designed to hold a value of one US dollar, backed by reserves. USDC is issued by Circle and USDT by Tether; together they account for the large majority of stablecoin settlement volume. If you want the plain-English background, ethereum.org's stablecoin overview is a good, neutral primer.

For a merchant, the appeal is concrete: a buyer anywhere in the world can pay in dollars without a card, the payment is final once it confirms on-chain (no card-style chargebacks), and you are not exposed to the price swings of volatile crypto because the token tracks the dollar.

  • Global reach, anyone with an EVM wallet can pay, no card network required.
  • On-chain finality after confirmation, no chargebacks months later.
  • Dollar-denominated, you receive a stable value, not a volatile asset.
  • Lower fees than card rails on many transaction sizes.

Which networks and wallets do you need to support?

USDC and USDT exist as ERC-20 tokens on Ethereum and on every major EVM-compatible chain. InfraIO Pay settles on Ethereum, Base, Polygon, BNB Chain, Arbitrum, and Optimism out of the box, and any other EVM chain on request. You choose which token-and-network combinations you accept; the buyer only ever sees the ones you allow.

On the buyer side there is nothing to install beyond a wallet they already have, MetaMask, Trust, Coinbase Wallet, Rainbow, or any WalletConnect-compatible app. The buyer scans a QR code or connects their wallet, and pays.

InfraIO checkout QR code and deposit address for paying a stablecoin invoice
Step two: the buyer scans the QR or connects a wallet to pay the exact amount.

How do you add a crypto checkout without writing code?

The fastest path is a payment link. From the dashboard you create a link for a fixed amount, share the URL anywhere, an invoice, a DM, a checkout button, and receive a webhook the moment it is paid. No SDK, no server, no checkout to build.

  • Create a link with an amount and the tokens/networks you accept.
  • Share the URL; the buyer opens it and pays from any wallet.
  • Get a signed webhook on payment, and the funds sweep to your wallet.

How do you integrate the checkout into your own site?

When you want checkout inside your own pages, drop in the web SDK and open it as a popup, redirect, or embedded iframe. When you want full control, call the server-side QuickCheckout API: one request creates the order and the session and hands you a hosted checkout URL.

If you need a token beyond USDC and USDT, you can list any verified ERC-20 contract from the dashboard, the standard is defined in EIP-20, and the same checkout flow handles it. See the pricing page for how the take rate works.

Who holds the funds, and when do they settle?

InfraIO Pay is non-custodial. Each order is paid into its own deterministic deposit address, then swept on-chain to the settlement wallet you connected once the transaction confirms. There is no PSP house account pooling buyer money and no withdrawal queue, the dollars land in a wallet whose keys only you hold.

You are charged only when a payment actually settles; failed and cancelled sessions cost nothing, and the take rate drops automatically with your monthly volume.