IGST export refunds extended; rectification via Officer Interface and CA reconciliation required for GST return mismatches. Extension permits rectification through the Officer Interface for shipping bills filed up to 31 July 2019 for errors including SB005 (invoice mismatch), SB003 (GSTIN mismatch), SB000 (IGST not reflected) and short refunds; affected exporters must submit reconciliation and rectification details to the IGST Refund Cell (Port). For cases where GSTN-to-Customs transmission failed due to payment mismatches between GSTR-1 and GSTR-3B, the procedures of the earlier circular apply mutatis mutandis for the April-March 2018-19 period, and a CA certificate confirming no discrepancy between refunded and paid IGST for that period must be furnished.