Answer:
If your institution has the ability to allocate information reporting between the SSN and the EIN for the calendar year of the change, using the same account number should not be a problem. Here, you are not attempting to change ownership via account maintenance, something bankers often do. You are simply trying to accomodate a routine change in the TIN when the trust becomes irrevocable.
First published on BankersOnline.com 5/30/11