Explanation
Monthly GST reconciliation is the process of matching: (1) your purchase invoices against GSTR-2B to identify ITC that can safely be claimed; (2) your sales register / GSTR-1 against GSTR-3B to confirm liability matches; (3) GSTR-2B vs GSTR-3B to ensure ITC claimed does not exceed 2B. Mismatches cause: DRC-01C (ITC excess over 2B), DRC-01B (3B tax short vs GSTR-1). Key rule: claim ITC only for invoices in GSTR-2B and paid within 180 days. Reconciliation should be done BEFORE filing GSTR-3B each month to avoid auto-notices. Verify on the GST portal before filing.