If you are registered under GST, you will file both GSTR-1 and GSTR-3B every month or quarter, and mismatches between the two are one of the most common causes of GST notices.
GSTR-1: Your Sales Details
GSTR-1 is a detailed, invoice-wise statement of all your outward supplies (sales) for the period. This is what feeds into your buyers' GSTR-2A/2B, so accuracy here directly affects your customers' ability to claim input tax credit.
GSTR-3B: Your Summary Return
GSTR-3B is a summary return where you declare your total sales, purchases, and pay the net GST due. It is simpler than GSTR-1 but still needs to reconcile with it.
Why Reconciliation Matters
When the figures in GSTR-1 and GSTR-3B do not match, or when your GSTR-2A/2B does not align with the input tax credit you have claimed, it is a common trigger for a GST department notice.
HATS reconciles GSTR-1, GSTR-3B and GSTR-2A every filing cycle as part of our GST return filing service, specifically to catch mismatches before the department does.