IGST refund processing: officer-assisted corrections and a PAN-based GSTIN mismatch remedy streamline export refund claims. Extension of officer-assisted correction for IGST refund processing is authorised to address SB005 invoice mismatches, requiring exporters to align invoice data with GST filings. A correction facility for SB003 cases is provided where differing GSTINs share the same PAN, conditional on a signed undertaking from both entities that the paying office will not claim refund or benefit; DG Systems has developed a correction utility to process such refunds.