Vendor filed invoice less amount in GSTR1

A supplier has incorrectly filed their GSTR1 with a lower taxable and GST amount than the actual invoice value. Since the GSTR1 has already been amended with other invoices, the specific incorrect invoice cannot be directly changed. The discussion explores how to reconcile this discrepancy with the buyer's ERP, considering options like issuing a debit note or writing off the difference. It also addresses scenarios where the amendment period for GSTR1 has passed.