GSTR-2B is an auto-drafted, static statement of the input tax credit available to a registered person for a tax period, generated from the returns their suppliers have filed. Unlike GSTR-2A, which keeps changing as suppliers file late, 2B is fixed once generated. That makes it the correct reference point for reconciliation, because it does not move under you.
Why 2B rather than 2A
GSTR-2A is dynamic: it updates whenever a supplier files or amends. Reconcile against it in September and you get a different answer in November, which means your working paper cannot be reperformed. GSTR-2B is generated once for a tax period and does not change afterwards, so a reconciliation against it is reproducible — which is the whole point of documentation.
In practice you want all twelve monthly 2B statements for the financial year, plus the statements for the first few months of the following year, because credits relating to the year under audit often appear there.
The six difference categories
Every difference between credit claimed in the books and credit available per 2B falls into one of six categories. Dumping them as a single list of mismatches is the most common failing in this working paper — it makes a 300-line difference impossible to conclude on. Categorised, the same 300 lines usually collapse into a handful of real issues.
| Category | What it means | Usual cause | Audit implication |
|---|---|---|---|
| Timing | The invoice appears in a different tax period in 2B than in the books | Supplier filed in a later month; or the client booked the invoice on receipt rather than invoice date | Usually not a misstatement. Confirm the credit appears in a subsequent 2B. Becomes an issue only if it crosses the year end and the deadline for claiming has passed. |
| Supplier has not filed | Credit claimed in the books, invoice absent from every 2B | The supplier has not filed GSTR-1, or filed with the wrong GSTIN | The credit may not be available. Quantify it, check whether it appeared in a later period, and consider whether a provision or disclosure is needed. |
| Ineligible credit | Credit claimed on a supply that is blocked | Categories blocked under section 17(5) of the CGST Act — motor vehicles, food and beverages, club memberships, works contracts for immovable property, goods written off, among others | This is a real exception. Credit claimed on a blocked supply is an overstatement of ITC and, if material, of profit. |
| Rate or value mismatch | The invoice appears in both but with a different taxable value or tax rate | Debit or credit notes not matched; rounding; genuine rate disputes; data entry | Usually small individually. Aggregate them before concluding — a pattern of one-sided differences is more interesting than any single line. |
| GSTIN mismatch | Credit recorded against the wrong registration | Multi-state clients where the supplier billed one GSTIN and the client booked it under another | Matters for entities registered in more than one state. Check whether the credit is available at all in the state where it was claimed. |
| Reverse charge | Appears in the books but not in 2B, correctly | Supplies liable to tax under reverse charge are not reported by the supplier in this way | Not a difference at all once identified. Excluding these first removes a large share of apparent mismatches. |
How to run the reconciliation
- 01Match on invoice number, supplier GSTIN and taxable valueMatch on all three rather than any one. Invoice numbering restarts each year at many suppliers, so invoice number alone produces false matches.
- 02Strip out reverse-charge supplies before anything elseThey are a category of expected difference, not an exception, and they otherwise inflate the unmatched list enough to hide the items that matter.
- 03Categorise every remaining differenceEach unmatched line belongs in exactly one of the six categories above. An uncategorised residue means the reconciliation is not finished.
- 04Quantify by category, then conclude by categoryThe conclusion on timing differences is different from the conclusion on ineligible credit. A single blended conclusion on 'ITC differences' is not a conclusion.
GSTR-2B generation dates, the deadline for claiming credit for a financial year, and the list of blocked credits under section 17(5) have all changed since GST was introduced and may change again. Verify the current position before concluding — do not rely on what was true in a prior year's file.
This is practical guidance written for audit teams, not an authoritative statement of any standard or statute. Standards, forms and timelines change. Check the current text issued by the ICAI and the relevant authority before relying on anything here in an audit file.
Related resources
- GST & GSTR-2BGSTR-2B reconciliation: a practical guide for auditorsWhat GSTR-2B is, how the Invoice Management System changed it, the statutory conditions that govern input credit, and how to run and conclude the reconciliation.
- GST & GSTR-2BInvestigating ITC mismatches during auditA decision path for an ITC mismatch: available, eligible, still claimable. What the client can do about each outcome, and how to quantify credit at risk.
- GST & GSTR-2BGSTR-2B vs purchase register: how to investigate differencesThe two documents record different events on different bases. Which differences are structural and expected, how to match the files reliably, and how to work one down to a cause.
- GST & GSTR-2BTwelve GST reconciliation mistakes that show up in audit filesPooling registrations, reconciling against 2A, stopping at March, netting categories and eight more errors, with what each causes and how to correct it.
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