Reviewed by Finin2min Editorial Desk · Last Reviewed 12 September 2026
Compare outward liability reported in GSTR-1 with GSTR-3B and input tax credit in GSTR-2B with GSTR-3B by tax period.
2-minute answer
GST return reconciliation tool for liability and ITC differences across GSTR-1, GSTR-3B and GSTR-2B.
Current-law note: Reviewed on 12 September 2026. Check any later amendment, notification, circular, deadline or portal instruction before taking action.
How to use this page
Use the page as a decision tool: keep inputs on the same basis, make assumptions explicit and test a downside scenario before relying on the output.
Practical checklist
Use dated statements or contracts rather than rough estimates where possible.
Keep monthly/annual and pre-tax/post-tax units consistent.
Test at least one conservative scenario.
Record the assumption that most changes the result.
Reviewed: 12 September 2026. The applicable statute, rule, notification, order or official filing instruction prevails.
Reconcile a tax period
Use invoice-level records before treating a difference as tax short-payment or excess ITC.
Adjusted outward-tax difference
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Adjusted ITC difference
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How This Is Calculated
This tool checks two key reconciliations: outward liability (adjusted GSTR-1 outward supplies versus GSTR-3B outward tax reported) and input tax credit (GSTR-3B ITC claimed versus adjusted GSTR-2B eligible credit). Mismatches beyond your entered tolerance flag either a short-payment/excess-reporting risk (liability side) or an over-claimed/under-claimed credit risk (ITC side), both of which are common triggers for GST department notices.
Frequently Asked Questions
Why does GSTR-1 vs GSTR-3B mismatch matter? ▼
GSTR-1 reports your outward supplies (what you sold), while GSTR-3B is where you actually pay tax. A mismatch — GSTR-3B liability lower than adjusted GSTR-1 — is one of the most common triggers for a GST department notice, since it suggests under-payment of declared liability.
Why does GSTR-3B ITC vs GSTR-2B mismatch matter? ▼
GSTR-2B shows ITC actually reported by your suppliers. Claiming more ITC in GSTR-3B than reflected in GSTR-2B is a red flag for excess credit claims and can lead to demand notices, interest, and reversal requirements.
What is a reasonable tolerance for these reconciliations? ▼
Small differences can arise from timing (a supplier reporting late) or rounding — a small tolerance avoids flagging trivial mismatches, but the right tolerance depends on your transaction volume and risk appetite. Persistent or large mismatches should always be investigated regardless of tolerance.
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.
Finin2min current-source control — Reconciliation scope control
Reviewed: 22 August 2026. This module adds a source/currentness/evidence control without changing the existing page identity or functionality.
A reconciliation difference is an investigation signal, not by itself an ITC entitlement/disallowance conclusion. Resolve invoice identity, period, amendments, credit notes, supplier filing/status and statutory conditions before deciding treatment. This batch must not change tool logic.
Practical verification checklist
Preserve source return/statement files.
Classify timing vs permanent differences.
Link each adjustment to statutory/portal evidence.
Use the controlling statute, notified rule/instrument, official portal and later authoritative treatment for the relevant date. This page remains an educational/professional reference.
Methodology, assumptions and sources
Scope: Reconciles data across GSTR-1 (outward supplies reported by the taxpayer), GSTR-3B (summary return with tax payment) and GSTR-2B (auto-generated ITC statement from suppliers' filings), flagging mismatches relevant to ITC eligibility and liability accuracy.
Calculation logic
Compare total outward tax liability reported in GSTR-1 against the tax paid/reported in GSTR-3B for the same period — a mismatch here can trigger a system-generated notice (e.g., under Rule 88C for GSTR-1 vs GSTR-3B liability differences).
Compare ITC claimed in GSTR-3B against ITC auto-populated in GSTR-2B (sourced from suppliers' GSTR-1/IFF filings) — claiming ITC materially in excess of GSTR-2B can trigger restrictions/notices under Rule 88D and the ITC-matching framework introduced via Section 16(2)(aa).
Flag specific line-item mismatches (missing supplier invoices in GSTR-2B, duplicate entries, rate/value discrepancies) for the taxpayer to follow up with the relevant supplier or correct in a subsequent return.
Inputs and assumptions
Reconciliation logic follows the current GSTR-1/3B/2B matching framework and the specific tolerance/notice-trigger rules under Rules 88C and 88D as currently in force.
GSTR-2B is treated as the authoritative source for ITC eligibility timing (static, generated monthly) rather than the dynamic GSTR-2A, consistent with the current ITC-claim framework under Rule 36(4)/Section 16(2)(aa).
Exclusions and edge cases
This is a comparison/reconciliation tool based on the data the user uploads/enters — it does not itself pull live data from the GST portal via API integration unless the user has separately exported and provided that data.
Does not itself file any correction, DRC-01C reply, or amended return — mismatches identified must be resolved through the appropriate GST portal workflow.