GSTR-2B reconciliation — how to match your ITC.

What is GSTR-2B (and how it differs from GSTR-2A)

GSTR-2B is an auto-drafted statement of the input tax credit available to you for a tax period, generated once a month from your suppliers' GSTR-1, IFF and GSTR-5 filings up to the 13th of the following month. Once generated, it's static — it does not change, which is exactly why it's the document actually used to work out how much ITC to claim in GSTR-3B.

GSTR-2A, by contrast, is dynamic — it updates continuously as suppliers file or amend returns, so checking it on the 5th and the 25th of the same month can give different numbers. That makes 2A useful as a running preview, but unreliable as the basis for a return you're about to file.

See our GST guide for how ITC and return filing fit together more broadly.

Why reconcile 2B against your purchase register

GSTR-2B reflects what your suppliers reported — not necessarily what you actually received, recorded, or are entitled to claim. The two rarely line up perfectly on the first pass. Reconciling them before you file GSTR-3B means you catch mismatches while there's still time to act — chase a supplier, correct an entry, or hold back a claim — instead of discovering a gap after filing, when the fix is a notice, a reversal with interest, or a credit you've lost the window to claim.

Claim too much ITC (credit that isn't in your 2B) and you risk a demand notice with interest. Claim too little (credit that is in your 2B but you missed in your books) and you're paying more cash tax than you need to. Reconciliation is what closes that gap in both directions.

How to reconcile manually in Excel

1. Download GSTR-2B from the GST portal for the period, as a CSV or JSON export.
2. Export your purchase register for the same period from your accounting books — supplier GSTIN, invoice number, invoice date, taxable value, tax amount.
3. Match rows by supplier GSTIN and invoice number using a lookup formula (VLOOKUP/XLOOKUP or a pivot) between the two sheets.
4. Flag one-sided entries — invoices in your register with no match in 2B, and invoices in 2B with no match in your register.
5. Check matched rows for value differences — compare taxable value and tax amount line by line; even a matched invoice can carry a mismatch here.
6. Investigate each flag — is it a late filing, a GSTIN error, an invoice number typo, or a genuinely missing invoice on either side?
7. Total up clean, matched ITC and use that figure — not your purchase register total — to fill GSTR-3B.

This is entirely mechanical, which is also why it's tedious and error-prone once you're past a few dozen invoices a month.

Common causes of mismatch

• Supplier filed their GSTR-1 late — after the 13th cut-off, so it missed this month's 2B and lands in next month's instead.
• Wrong GSTIN entered by the supplier — the invoice exists but is attributed to a different buyer.
• Invoice number mismatch — a typo or a different numbering format between your purchase register and the supplier's filing.
• Invoice value or tax amount doesn't match — rounding, a post-invoice discount, or a data entry error on either side.
• Missing invoices entirely — supplier hasn't filed, filed under the wrong period, or the purchase wasn't recorded on your side at all.

We've written up the detail on each of these, with what to do about them, in GSTR-2B mismatch — 7 causes. A related and equally common issue on the sales side — an inter-state sale posted to a local ledger — is covered in our sales ledger mismatch detector post.

How TatvaBooks automates it

This is one of the core things TatvaBooks does. We pull your GSTR-2B directly and match it line by line against your purchase register — by supplier GSTIN, invoice number and value — automatically, every period. Anything that doesn't match is flagged clearly: late filing, GSTIN mismatch, invoice number mismatch, or value difference, with the reason shown so you know exactly what to chase.

You see your clean, matched ITC figure before you file GSTR-3B — not after, when a mismatch has already become a notice. This is the difference between reconciliation as a monthly fire drill and reconciliation as something that just happens in the background as you record purchases. It works alongside GST-correct invoicing on the sales side — see GST billing software and sale voucher.

As with everything TatvaBooks prepares: we get your ITC workings right and ready — you still review and file on the GST portal yourself. We don't file on your behalf.

Frequently asked questions