Duty concession for capital goods tied to mandated export obligation ensures conditional import relief and compliance mechanisms. The EPCG scheme permits capital goods imports at concessional or nil duty in return for a specified export obligation tied to a duty-saved amount. Authorizations issued by Regional Authorities require Nexus Certificates from independent Chartered Engineers and installation certificates; they specify import registration port, export products and terms for spares and leasing. Export obligations are block wise with proportionate fulfilment, automatic tolerances for limited excess/shortfall, mechanisms for extension on composition or duty deposit, and procedures for redemption, recordkeeping, re-export or replacement of defective goods, and enforcement under trade and customs law.