Answer:
There is no requirement to place the FDIC logo on your stationery and if the letter you are sending is not a direct or indirect advertisement for an insured deposit product, there is no requirements to have it in the letter.
[Editor's note: A bank never has to use the FDIC logo on advertising. It can use the membership statement, which is often shortened to "Member FDIC" when the FDIC's rules require it. As Randy points out, it's not required for the use asked about.
First published on BankersOnline.com 4/22/13