No, UK here, I didn’t mean the account number or sort code. I meant if you were sending someone say £1,000 if I add a 0 that’s £10k sent. Nothing will stop it unless fraud flag it or there isn’t enough money in the account, it then needs to be approved. But if the funds are there it’s gone and the only way to get it back is by requesting the other bank to block access to those funds and return them. The systems are not that robust and mistakes do happen.

You’re right about the account checks but major banks use COP to confirm account details match the name but again that can be spoofed and scammers use this to impersonate people.