GSTR-1, GSTR-2B and GSTR-3B: which GST return is which, and how they interlock

A regular GST taxpayer deals with three documents each cycle, and confusing them is the most common filing error. The trick is to see them as one pipeline, not three separate tasks.

GSTR-1 is your outward story: every sale invoice you raised. GSTR-2B is your inward story, drafted for you: the credit your suppliers' filings entitle you to. GSTR-3B is the settlement: tax due on sales, minus the credit, paid in cash for the rest.

• →GSTR-1: the outward-supplies return you file, listing every sales invoice, under Section 37 of the CGST Act^[1].
• →GSTR-2B: an auto-drafted, static input tax credit statement the portal generates for you under Rule 60(7)^[3]. You do not file it; you read and reconcile it.
• →GSTR-3B: the summary return where you declare net tax, claim the credit, add reverse charge, and pay, under Section 39^[2].
• →Why it matters: filing GSTR-3B before you reconcile GSTR-2B is how businesses over-claim credit and invite a Section 16 mismatch notice.

GSTR-1 carries your B2B invoices at the line level, your B2C sales in summary, credit and debit notes, exports, and any amendments to earlier periods. Nothing you sell escapes it.

It matters beyond your own file: the data you enter in GSTR-1 flows straight into each buyer's GSTR-2B. A missed or wrong invoice here becomes your customer's missing credit there, which is why buyers chase suppliers who file late.

• →What it holds: B2B invoices line by line, B2C sales in summary, credit/debit notes, exports, and amendments, drawn from the tax invoices you raise under Rule 46.
• →Who files it: every regular registered taxpayer; a nil GSTR-1 is still required for a period with no sales.
• →When: the 11th of the following month if you file monthly, or the 13th of the month after the quarter under the QRMP scheme, per Rule 59^[4]. QRMP filers can push B2B invoices early each of the first two months via the optional Invoice Furnishing Facility.
• →Why accuracy matters: your GSTR-1 is your buyer's credit. Under Section 16(2)(aa)^[5], a buyer can claim credit only for an invoice that appears in their GSTR-2B, which is built from your GSTR-1.

The portal reads every supplier's GSTR-1 (and the IFF and import data) and assembles the credit available to you for the period. "Static" is the key word: once generated for a month, GSTR-2B does not change, so two people looking at it see the same figure. That fixed snapshot is what makes it the reconciliation benchmark.

Do not confuse it with GSTR-2A, which is dynamic and keeps updating as suppliers file late. GSTR-2B is the frozen, official basis for your credit claim.

• →Nature: auto-drafted and static; a read-only statement, not a return you submit.
• →Source: your suppliers' GSTR-1 and IFF filings, plus import and reverse-charge data, assembled by the portal.
• →Generated: on the 14th of the month following the return period, so it lands before the GSTR-3B due date, giving you a window to reconcile.
• →Use: it is the benchmark for the credit you claim in GSTR-3B. Credit sitting in GSTR-2B but not on your books, or on your books but not in GSTR-2B, is exactly what a reconciliation surfaces before you file.

GSTR-3B is a summary, not an invoice-level return: consolidated figures for outward tax, input tax credit, and the net payable. You settle credit from the electronic credit ledger and the rest from the electronic cash ledger.

This is also where reverse charge is discharged. If you owe GST as the recipient on a notified supply, you declare and pay it here, in cash, and cannot set it off from existing credit.

• →What it does: nets output tax against the input tax credit that GSTR-2B supports, adds reverse charge, and settles the balance.
• →Where money moves: credit discharges from the credit ledger; the remaining tax, and all reverse-charge tax, is paid in cash from the cash ledger.
• →Reverse charge lives here: an RCM liability is declared and paid in GSTR-3B. See when a small business pays GST for its supplier.
• →When: the 20th of the following month if you file monthly, or the 22nd or 24th of the month after the quarter under QRMP, by state group, per Rule 61^[4]. Late payment carries interest under Section 50.

Read it as a relay where each hand-off depends on the one before it. You raise invoices and report them in GSTR-1. The portal takes every supplier's GSTR-1 and drafts each buyer a GSTR-2B. You check your GSTR-2B against your purchase records, then carry the agreed credit into GSTR-3B and pay.

• →GSTR-1 out, GSTR-2B in: the same invoice you report as an outward supply becomes your buyer's inward credit line.
• →Reconcile in the middle: the gap between GSTR-2B and your books is fixed before, not after, you file GSTR-3B.
• →GSTR-3B settles: only the credit GSTR-2B supports is safely claimed; the rest of the tax is paid in cash.
• →Why the order is fixed: skipping the GSTR-2B reconciliation is what turns a supplier's late filing into your Section 16 credit mismatch.

These are the standard notified dates. The QRMP scheme, for taxpayers with turnover up to Rs. 5 crore, lets you file GSTR-1 and GSTR-3B quarterly while paying tax monthly by challan.

One caution: the CBIC extends these dates by notification more often than you would expect, usually when the portal is under load. Always confirm the live due date on the GST portal^[6] before you file, rather than relying on a fixed calendar.

• →GSTR-1: 11th of the following month (monthly); 13th of the month after the quarter (QRMP), per Rule 59^[4].
• →GSTR-2B: generated on the 14th of the following month; not filed, so it has no due date of its own, only a generation date.
• →GSTR-3B: 20th of the following month (monthly); 22nd for Group 1 states or 24th for Group 2 states after the quarter (QRMP), per Rule 61^[4].
• →Caveat: any of these can be extended by CBIC notification. The dates above are the default rule, not a guarantee for a given month, so check the current date on the portal^[6].