Import manifest amendment: minor changes approved administratively same day; shipping lines bear amendment responsibility and fees. The circular prescribes distinct administrative procedures for IGM amendments: same day approval of minor amendments by Superintendent/Appraiser without adjudication (subject to a revised flat amendment fee), general 24 hour processing for major amendments by Deputy/Assistant Commissioners with escalation for delays, mandatory combined application by the shipping line with specified supporting documents, and allocation of liability for any penalties to the shipping line filing the IGM under section 30; consignees and brokers are exempt from such fines.