how to correct an e file error using the wrong bank account number
It's not possible to correct. Client will receive a check if bank account isn't active.
It's Sunday today - go to church and pray for a rejection.
An Efile error? meaning it wont let you Efile until you fix a number?
Or your error, meaning you transmitted a return with the incorrect bank account number on it?
It is a good idea to ask the client for a check marked void, to use to enter the bank information and then triple check it for accuracy before e-filing. Just my opinion.
You only triple check it? You must run really fast with those super sharp scissors 😉