Answer:
No "extra" documents are required; i.e. if it is an interest bearing account the TIN certification will suffice. Otherwise, you do not need anything.
The LLC may use the TIN of a single member (includes corporations and another LLC) if the LLC is "disregarded" for income tax purposes. That affects the single member's income tax return, but it has nothing to do with the bank's responsibilities.
First published on BankersOnline.com 2/11/13