What Happens to the Remaining Allowance If a Contract Only Uses a Portion of It?
The remaining allowance persists and can be used by the contract in future transactions. If a user approves 100 tokens and the contract pulls 20, an allowance of 80 tokens remains active.
The contract can pull these 80 tokens at any time in the future without further user permission. This is why managing allowances is crucial; a forgotten, large allowance to a rarely used dApp is a dormant security risk.
