IGST export refund requires PFMS bank-account validation; exporters must update and maintain bank details for disbursal. Exporters must validate their bank accounts in PFMS to receive electronic IGST export refunds; the shipping bill functions as the refund application from 01/07/2017 and a refund claim is deemed filed only after EGM filing and filing a valid Form GSTR-3. PFMS rejections (closed accounts, invalid IFSC/account, missing tags, duplicate or malformed records, beneficiary or bank-master mismatches) prevent crediting of sanctioned refunds. A published list of non-validated accounts for Cochin Custom House/Cochin Air Cargo is provided and exporters are directed to update details immediately and report difficulties to Customs (Drawback/EDI).