In my professional practice ... we adopted the $1 rule for the unknown stimulus amount. If the client could not remember or figure out if they got the stimulus advance then we entered in the program that they got all of it EXCEPT $1 which put a $1 credit on line 30 which forced the IRS to reconcile the credit. If they did get the advance then the refund would be $1 less or they would owe $1 more. If they did not get all or any of the advance then the refund would be pleasantly higher or they would owe less. This way it was good news in either direction and I was a "hero" and not the bearer of bad news.
