Document retention obligations for customs audits require timely production and cooperation with audit officers. Auditee must preserve and, on request by the proper officer, promptly make available true and correct information, records and documents, including electronic records, maintained under applicable customs law in relation to imported, export or dutiable goods for a minimum prescribed retention period. The auditee must assist the proper officer and the officer's team in discharging their duties and must not refuse or obstruct them during audit.