What Happens to a Token Allowance If the Dapp’s Smart Contract Is Upgraded or Changed?

The token allowance is tied to a specific smart contract address. If a dApp upgrades to a new smart contract, any allowances granted to the old contract address are not automatically transferred.

The old allowance remains active but is now irrelevant to the new, upgraded dApp. The user must grant a new token allowance to the new smart contract address to interact with the upgraded protocol.

The old allowance should still be revoked as a security best practice.