Deferred payment of customs duty extended to authorised public undertakings, with mandatory e-payment for specified importers and AEOs. Payment of customs duty may be made via TR-6 Challan at designated banks or through electronic payment channels; e-payment is mandatory for importers under the Accredited Clients Programme/Authorised Economic Operator scheme and for importers meeting the prescribed duty threshold per Bill of Entry. A deferred payment regime permits qualified Authorised Economic Operator participants to defer import duty under the Deferred Payment of Import Duty Rules, and the deferred facility has been extended to Authorised Public Undertakings consistent with the statutory proviso.