Advance licence duty exemption conditioned on DEEC compliance and customs procedures for imported materials and export obligation discharge requirement. Exemption from customs duty for materials imported under an Advance Licence is subject to production of a Quantity Based Duty Exemption Entitlement Certificate (DEEC), debit entry at customs, execution of a bond or undertaking and declaration to pay duty on demand for non compliance. Imports are limited to specified ports unless specially permitted; export obligation must be discharged within the DEEC period or any authorised extension, and materials must be used solely to meet that obligation until discharge and realisation of proceeds. Transferability and post discharge use are restricted and governed by licensing endorsements, with special rules for certain licences and Acetic Anhydride. Default attracts duty and interest limits on regularisation.