> For the complete documentation index, see [llms.txt](https://wallet-basics-guide.gitbook.io/wallet-basics-guide-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wallet-basics-guide.gitbook.io/wallet-basics-guide-docs/how-to-fix-stale-token-allowances-before-a-bridge-call.md).

# How to fix stale token allowances before a bridge call

A token allowance must cover the amount a bridge will spend: an approval for 99 USDT cannot cover a 100 USDT deposit. An allowance is permission you give a contract to move a specific token from your wallet. [Mantle Bridge deposit](https://dev.to/mark-eth/mantle-bridge-allowances-for-repeat-treasury-deposits-8pi) lets you check the approval for the token and spender before you submit the bridge call.

### What does a token allowance remember?

An allowance is recorded for one token, one wallet, and one spender contract on one network. The spender is the contract allowed to move your tokens; it may be the bridge contract or another contract the bridge flow names.

When you approve 100 USDT, the token contract records that permission. A later bridge call asks the token contract to move your USDT using that permission. Spending tokens usually reduces the allowance, so a previous approval may now be too small.

Allowances are separate from your balance. You can have 150 USDT in your wallet but only 20 USDT approved for the spender. ETH sent as ETH does not use an ERC-20 token allowance; this check applies to tokens such as USDT.

### How can you tell if an approval is stale?

Compare the allowance with the amount you plan to bridge, then check that it belongs to the correct token, wallet, spender, and network. If any one of these differs, the approval may not help your current transaction.

A common mistake is approving a token once, then returning later and assuming the approval still covers the next deposit. For example, you approved 100 USDT, bridged 70, and now want to bridge 40. If the token uses the usual allowance rules, only 30 remains; approve at least 10 more before retrying.

Check the bridge screen for the token and spender details. If your wallet or a block explorer offers a token allowance view, compare its allowance with the bridge amount. A displayed allowance for a different spender or network is not the permission this call needs.

### What should you do before retrying?

If the allowance is too low or points to the wrong spender, use the bridge’s approval step for the selected token and amount. Read the wallet prompt: it should name the token and show the permission amount. A limited approval for the amount you intend to send reduces how much the contract can move later.

Some tokens, including certain USDT versions, may reject changing one nonzero allowance directly to another. If the wallet reports that error, set the allowance to zero first, wait for that transaction to confirm, then approve the needed amount. Each approval is a separate transaction and can cost network gas.

After approval confirms on the source network, reopen the bridge screen and check the amount again before submitting the bridge transaction. The approval lets the contract spend tokens; it does not move them by itself.

* Check the token, wallet, spender, and source network.
* Make sure the allowance covers the amount you will send.
* Approve only what you need, then submit the bridge call after confirmation.