Theoretically, the excess part is invalid; But in fact, you signed a blank contract, and the other party immediately filled in the numbers himself, because the time interval was short and there was no way to identify the notes. In addition, as adults, when signing a contract, they should pay attention to the terms of the contract, have the obligation to review the contents of the contract, and should be aware of the risks of signing a blank contract. If you can't overturn the actual loan amount and provide sufficient evidence, you will bear adverse consequences.