Closing Fee

A suggestion has been made that we consider charging a "closing fee" on DDA and Savings accounts. Example if customer closes account within 90 days of opening we'd charge $X. I know this would have to be disclosed in TISA disclosures, but does this create any other issues? My concern is would we have inadvertently placed a term on an account, thereby negating it as a DDA?

These fees are common and are meant to compensate the bank for the work that went into setting up the account. It doesn't change any account structures.

Thanks Andy...