This could be a fairly complex answer, depending on some specifics.
First off, most of the advertising reguirements come out of Regulation DD, which only applies to an account which is "held by or offered to a consumer." Therefore, your business checking products may be exempt, depending on whether or not you offer them to consumers, such as allowing sole proprietors to open these types of accounts.
Secondly, you may have an issue with your rate sheet if you included it in your mailing. A rate sheet, when handed to customers, is considered an advertisement. If the rate sheet includes rates for consumer products, then you should have all applicable disclosures (which is more than just Member FDIC) on the rate sheet as an APR is a trigger term. The full advertising requirements can be found in section 230.8 of regulation DD.
I do not know of a requirement to maintain the names and addresses of targeted businesses. I believe it to be a best practice (and a requirement of our examiners) to retain copies of all advertisements, including letters.
_________________________
Adam Witmer, CRCM
All statements are my opinion, not those of my employer, and should not be taken as legal advice.
www.compliancecohort.com