Stablecoin payments on Ethereum

Ethereum’s role in stablecoin payments is that of the universal fallback: always supported, rarely the best choice.

When mainnet is the right call

Large payments. The fee is fixed regardless of amount, so a $4 transaction cost is 0.08% of a $5,000 invoice and 44% of a $9 one. Above roughly a thousand dollars, mainnet’s cost stops mattering and its liquidity and universal support start to.

It is also the right call when the merchant offers nothing else, which still happens with older integrations.

The gas token trap

The single most common problem people hit is a wallet holding stablecoins and no ETH. Gas is paid in the native token, so USDC cannot pay for its own transfer. The wallet will show a healthy balance and refuse to send.

Keep a small ETH balance — twenty or thirty dollars is comfortable — in any wallet you pay from. Some wallets and accounts now support paying fees in the token being sent, but it is not universal and you should not count on it at a checkout with a countdown running.

Bridged assets

Not all USDC on every chain is the same asset. Some chains carry both a natively issued version and an older bridged version from before native issuance existed. Merchants and gateways generally accept only the native one.

If your wallet shows something like “USDC.e” alongside “USDC”, they are different tokens. Check which one the merchant’s checkout expects before sending.