GST refund procedure requires electronic filing with prescribed documentary proof and acknowledgement, plus ledger adjustments for ITC refunds. Refund claims must be filed electronically in FORM GST RFD-1 with prescribed evidence specific to the refund ground; small claims require a declaration while larger claims need a professional certificate. Input tax credit refunds debit the electronic credit ledger. Zero-rated export refunds under bond/LOU are computed by a formula tying export turnover to net ITC and adjusted total turnover, and are disallowed if supplier avails drawback or rebate. Officers must acknowledge complete applications promptly and issue deficiency communications through prescribed forms, harmonising central and state procedures.