Two returns, two different jobs
GSTR-1 is a detailed, invoice-level report of everything you sold — it tells the government (and your customers' input tax credit claims) exactly what happened, line by line.
GSTR-3B is a summary return — total sales, total purchases, tax payable and tax paid — filed to actually settle your GST liability for the period.
Why they need to match
The tax authority cross-checks the summary numbers in your GSTR-3B against the detailed figures in your GSTR-1. A mismatch between the two is one of the most common triggers for a GST notice, even when both are individually correct.
This is exactly why LedgrBook generates both from the same underlying invoice data — there is no manual re-entry step where numbers can drift apart.
LedgrBook handles this automatically. The parts of this guide your bills already know.
See how →A simple monthly rhythm
Most small businesses file GSTR-1 by the 11th and GSTR-3B by the 20th of the following month. Keeping your billing current through the month — rather than batching it all at deadline — makes both filings a formality instead of a fire drill.
General information, not professional tax advice — confirm specifics with your CA.
