Zero-rated supply to SEZ permits supply under bond or payment with refund; supplies to domestic territory attract customs duties. Supplies of goods or services to a Special Economic Zone developer or unit are zero-rated supplies for GST, treated as exports; suppliers may supply under bond or LUT without IGST and claim Input Tax Credit, or pay IGST and claim refund. Supplies by or to an SEZ developer/unit to the domestic tariff area are subject to customs duties analogous to importation under the Customs Tariff Act.