GST & Indirect Tax

GSTR-1 vs GSTR-3B: What Each Return Covers and How to Reconcile Them

GSTR-1 vs GSTR-3B: How to Reconcile Them

CA Nikhil Gupta·June 2026· Filing Guide GST COMPLIANCE

Reviewed by CA Nikhil Gupta · Last reviewed 16 June 2026

GSTR-1 and GSTR-3B are the two returns every regular GST-registered business files every month (or quarter) — and they serve very different purposes. A mismatch between the two is one of the most common triggers for a GST department notice, so understanding what each return covers is essential.

GSTR-1: Statement of Outward Supplies

GSTR-1 is a detailed, invoice-level statement of all outward supplies (sales) made during the period — including B2B invoices, B2C transactions (summarised), exports, credit/debit notes, and amendments to previously reported invoices. This is the data that flows through to your customers' GSTR-2B (their auto-generated input tax credit statement), making accuracy in GSTR-1 critical not just for your own compliance but for your customers' ability to claim ITC.

GSTR-3B: Summary Return with Tax Payment

GSTR-3B is a monthly (or quarterly) summary return that consolidates total outward supplies, total inward supplies, eligible input tax credit, and the resulting net tax liability — and is the return through which the actual GST payment is made. Unlike GSTR-1, GSTR-3B does not require invoice-level detail; it works off aggregate figures.

Side-by-Side Comparison

Aspect	GSTR-1	GSTR-3B
Purpose	Reports outward supply details (invoice-level)	Summary return + tax payment
Level of detail	Invoice-wise	Aggregate/summary figures
Tax payment	No payment made here	Tax liability paid through this return
Impact on recipients	Feeds into recipients' GSTR-2B for ITC	No direct impact on recipients
Typical due date	11th of the following month (monthly filers)	20th of the following month (varies by turnover/state group)

Why Mismatches Happen

Since GSTR-1 (detailed sales data) and GSTR-3B (summary figures used for payment) are filed separately — often prepared by different processes or at different times — discrepancies commonly arise from:

An invoice reported in GSTR-1 but the corresponding tax amount not included in GSTR-3B's outward tax liability (or vice versa)
Amendments made in GSTR-1 for a later period that aren't correspondingly reflected in GSTR-3B for the same period
Credit notes issued and reported in GSTR-1 but not netted off correctly in GSTR-3B's taxable value
Rounding differences or data entry errors when figures are summarised manually from accounting software into the GSTR-3B summary

⚠ GSTR-1 vs GSTR-3B mismatch is a top trigger for GST notices: The GST department is automated scrutiny systems compare the tax liability declared in GSTR-3B against the outward supply value reported in GSTR-1 for the same period. A significant mismatch (liability in GSTR-3B lower than what GSTR-1 implies) commonly results in an automated notice (e.g., under ASMT-10/DRC-01B) asking for an explanation or requiring the shortfall to be paid with interest.

How to Reconcile GSTR-1 and GSTR-3B

Match total taxable value and tax amount reported in GSTR-1 for the period against the outward tax liability declared in GSTR-3B for the same period — they should align (subject to timing differences for amendments).
Account for credit/debit notes separately — ensure these are netted consistently in both returns for the same period.
Reconcile amendments — if invoices from a prior period were amended in the current period's GSTR-1, ensure the corresponding tax impact is reflected in the current period's GSTR-3B, not retroactively adjusted in the original period GSTR-3B (which has already been filed and generally cannot be revised).
Do this reconciliation monthly, not just annually — small discrepancies compound over the year and become much harder to trace and explain at annual return (GSTR-9) time.

The Annual Return Connection

At year-end, GSTR-9 (the annual return) requires reconciliation of the figures across all months' GSTR-1 and GSTR-3B filings, along with the audited financial statements (via GSTR-9C for businesses above the prescribed turnover threshold). Unresolved monthly mismatches accumulate into a much larger reconciliation exercise at this stage — making monthly discipline in matching GSTR-1 and GSTR-3B one of the highest-leverage compliance habits for a business.

2026 current-law quick reference

Finin2min answer: GSTR-1 reports outward-supply details while GSTR-3B is the summary return/payment mechanism; turnover/tax differences should be explained and corrected, not left as permanent reconciling items.

What changes the answer?

What to check	What to do	Common mistake to avoid
Core classification	GSTR-1 reports outward-supply details while GSTR-3B is the summary return/payment mechanism; turnover/tax differences should be explained and corrected, not left as permanent reconciling items.	Do not decide from the label used on an invoice, agreement or bank narration alone.
Edge case	Credit notes, amendments and timing differences can be legitimate, but each difference needs a document-level trail.	Recompute when the fact pattern crosses this boundary.
Evidence	Reconcile the documents below to the tax/regulatory return before filing.	A correct legal rule with an unreconciled evidence trail can still fail in assessment or audit.
Effective date	Apply the law/form/rate for the actual transaction, tax year or proceeding date.	Do not mix FY 2025–26/AY 2026–27 legacy references with post-1-April-2026 forms.

Worked practical example

Books show ₹50 lakh taxable outward supplies, GSTR-1 ₹49 lakh and 3B ₹50 lakh. Identify the missing/amended invoice before the next filing cycle.

Evidence checklist

sales register
GSTR-1/IFF
GSTR-3B
e-invoice data
amendment/credit-note log

Primary-source checks: CBIC — CGST Act · CBIC — ITC rules / GST Portal

How to use this: This current-law summary reflects the latest position. Where it conflicts with an older rate, threshold, form or section reference elsewhere on the page, rely on the current, dated primary source above.

Frequently Asked Questions

If I make a mistake in GSTR-1, can I correct it in a later month? ▼

Yes — GSTR-1 allows amendments to previously reported invoices in a subsequent period filing. However, the corresponding tax impact of that amendment needs to be reflected in the GSTR-3B of the period in which the amendment is made (the current period), not by revising the original period GSTR-3B, which generally cannot be revised once filed.

Does filing GSTR-1 mean I have paid my GST liability? ▼

No. GSTR-1 only reports the details of outward supplies — it does not involve any tax payment. The actual GST liability is computed and paid through GSTR-3B, which must be filed separately (and after GSTR-1 for the corresponding compliance to be complete for that period).

What happens if GSTR-1 and GSTR-3B figures consistently do not match? ▼

Persistent mismatches between GSTR-1 (outward supply value) and GSTR-3B (declared tax liability) are flagged by the GST departments automated systems and commonly result in a notice asking the taxpayer to explain the difference or pay the shortfall along with applicable interest. Repeated unexplained mismatches can also increase the likelihood of a detailed audit or scrutiny of the business GST compliance.

Source and review trail

Use the current official instrument, portal or regulator publication before acting. This panel separates the category authority from page-specific references.

Primary category: GST & Indirect Tax
Official starting point: www.gstcouncil.gov.in

Page source links

The prior page did not embed a page-specific external source. The category authority above is the minimum verification starting point; a specific instrument should be added when available.