What happens if FTB determines that the assignee receiving the credit assignment is not unitary with the assignor on the required dates for a valid assignment?
The assignment is invalid and the credit goes back to the assignor for future use, as if the election had not been made. The credit will be carried forward to a year subsequent to the failed assignment election year, and the assignor can either file an amended return to claim the credit for itself (assuming the statute of limitations is still open), or the assignor can assign the credit on an original return for a subsequent year if the credit has not expired.
