My organizer questionnaire asks for positive confirmation that the bank account hasn't changed. The body of the organizer has an area asking if the bank account is the same, and requesting details if it has.

ALL clients must complete the questionnaire and engagement letter (I let a few slide on the completed organizer...not many).

The tax return cover letter tells the client to verify the bank account info.

If the client misses THREE prompts - it's their problem.