# Wallet Approvals: Permissions You Forgot

URL: https://www.caijing188.com/wallet-approvals/
Published: 2026-10-27T16:56:49+08:00 | Updated: 2026-10-27T16:56:49+08:00
Verified: 2026-10-27

## Quick answer
An approval lets a contract spend a token later, without asking again. Unlimited is the default, so review old allowances and revoke what you cannot justify.

## Summary
A token approval is a standing permission another contract can use later. Unlimited approvals are the default, which is why old signatures drain wallets months after the trade.

## FAQ
Q: Does revoking an approval cost money?
A: Yes. Revoking is a transaction that writes a zero to the token contract, so it pays a network fee. On some chains the fee is trivial; on others it can rival the value of a small position.
Q: Can someone drain my wallet with an old approval?
A: Only the token and amount covered by that approval. They cannot move other tokens or the native coin, and they cannot sign anything new. Old approvals are dangerous because balances grow while permissions stay.
Q: Is an unlimited approval always unsafe?
A: No. It is a permission, and the risk depends on who holds it. An unlimited approval to a widely used, long-standing contract is a different proposition from one granted to a site you reached through an advertisement.
Q: How do I know an approval was granted?
A: The token contract emits an event when the allowance changes. Block explorers list these events, and approval checkers read them. If you did not see a confirmation, no approval was written.
Q: Does deleting the app or disconnecting my wallet help?
A: No. The allowance lives in the token contract, not in the application or in your wallet's connection state. Only a revoking transaction, or spending the allowance down, changes it.
Q: Do approval rules differ by jurisdiction?
A: The mechanics are the same everywhere, but how authorities treat authorised transfers, custody, and reporting varies. Rules differ by jurisdiction and change over time, so check what applies where you live.