12 CFR § 9.8 - Recordkeeping.
(a) Documentation of accounts. A national bank shall adequately document the establishment and termination of each fiduciary account and shall maintain adequate records for all fiduciary accounts.
(b) Retention of records. A national bank shall retain records described in paragraph (a) of this section for a period of three years from the later of the termination of the account or the termination of any litigation relating to the account.
(c) Separation of records. A national bank shall ensure that records described in paragraph (a) of this section are separate and distinct from other records of the bank.