How MetaMask Card Spends From a Wallet You Control

Most crypto cards hold your money for you. MetaMask Card does not — the tokens stay in your wallet until a purchase settles. That difference is implemented through an on-chain spending cap, and it is worth understanding, because it is also the thing you have to manage.

A spending cap is a standing on-chain permission, not a balance

A spending cap is an approval you sign on-chain. It lets the card draw up to a set amount of a specific token from your account, and nothing moves until a payment goes through. Because the approval is recorded on the blockchain, it stays in force until you sign another transaction that changes or removes it.

Practically, this means the cap is a standing permission rather than a balance. Setting it to a number far above what you spend does not make payments smoother; it only widens what could be drawn if something goes wrong.

Choosing tokens, and the order they are used

The card spends from USDC, USDT or wETH. You can enable more than one and set a priority order, so it draws from your preferred token first and falls back to the next when that runs short. If you keep most of your balance in one stablecoin and a little in another, putting the smaller one first is a simple way to keep the main holding untouched for ordinary purchases.

Revoking access

There are two routes, and both are on-chain transactions rather than settings toggles:

• In the card interface, open Enable tokens, pick the token, choose Edit limit and enter 0. MetaMask then asks you to confirm revoking the cap.
• In MetaMask Portfolio, the Overview tab has a Spending Caps section listing every active approval, each with a revoke button.

Either way you pay gas and the change takes effect when the transaction confirms, not the instant you tap the button. That lag matters if you are revoking in a hurry.

The cap bounds card-side exposure and nothing else

A cap bounds your exposure from the card side: whatever happens downstream, no more than the approved amount can be pulled. It does nothing about the rest of your security posture. It will not help if your seed phrase leaks, and it will not stop approvals you signed for other contracts entirely.

The practical habit is to keep the cap close to what you actually spend in a month and top it up deliberately, rather than approving a large number once and forgetting it exists. The extra gas is a few cents; the reduction in standing exposure is not.

For the fee side of the same card, see our breakdown of MetaMask Card in the comparison.