21 CFR 1305.27 - Preservation of electronic orders.
(a) A purchaser must, for each order filled, retain the original signed order and all linked records for that order for two years. The purchaser must also retain all copies of each unaccepted or defective order and each linked statement.
(b) A supplier must retain each original order filled and the linked records for two years.
(c) If electronic order records are maintained on a central server, the records must be readily retrievable at the registered location.