Rule 37A ITC reversal: the 30 November 2026 deadline, interest, and how to find exposed invoices

The invoice is in your GSTR-2B. You accepted it in IMS, claimed the ITC, and paid the supplier in full. Eight months later you discover the supplier filed GSTR-1 but never filed GSTR-3B, so the tax you paid them never reached the government. Under Rule 37A that credit has to come out of your books by 30 November, and if you are late it comes out with interest.

Today is 22 October 2026. For ITC availed in FY 2025-26, the supplier test date of 30 September 2026 has passed and the reversal date is five weeks away. This post explains what the rule says, how to find the exposed invoices, how to reverse and later re-avail, and how to make this a monthly routine instead of a November scramble.

What Rule 37A says

Rule 37A was inserted into the CGST Rules by Notification 26/2022-Central Tax dated 26 December 2022, following the 48th GST Council meeting. It gives effect to Section 41, which from 1 October 2022 makes ITC liable to reversal with interest where the supplier has not paid the tax, and to Section 16(2)(c), which conditions ITC on the tax having actually been paid to the government. The rule and its history are set out in Taxmann’s analysis and the rule text is reproduced by CA Club.

In plain terms:

1. You availed ITC on an invoice or debit note in a financial year.
2. The supplier reported that document in GSTR-1 or IFF (which is why it reached your 2B).
3. The supplier has not furnished GSTR-3B for that tax period by 30 September following the end of that financial year.
4. You must reverse the ITC in a GSTR-3B filed on or before 30 November following the end of that financial year.
5. If you do not, the amount is payable with interest under Section 50.
6. When the supplier later files that GSTR-3B, you may re-avail the credit in a subsequent GSTR-3B.

Two details in that table trip people up. The trigger is the year in which you availed the credit, not the invoice date: a March 2026 invoice whose ITC you claimed in April 2026 belongs to FY 2026-27 for Rule 37A. And a quarterly filer cannot file the October to December return before 30 November, so the only GSTR-3B a QRMP taxpayer can use for the FY 2025-26 reversal is the July to September 2026 return, due on 22 or 24 October 2026. That leaves barely three weeks after the 30 September test date.

Interest

Reverse by 30 November and there is no interest. The rule’s proviso attaches interest under Section 50 only where the reversal is made after that date. Section 50(3), as rewritten by the Finance Act 2022 with retrospective effect from 1 July 2017, charges interest on ITC that was “wrongly availed and utilised”. Notification 13/2017 originally fixed 24 per cent for this sub-section; the Finance Act 2022 substituted 18 per cent retrospectively, and Rule 88B computes the interest from the date the credit was utilised until it is reversed (TaxGuru). Some commentary, including a still-indexed ClearTax page, quotes 24 per cent; that is the statutory ceiling, not the notified rate.

There is an unresolved argument about when the clock starts for a late Rule 37A reversal: from the original date of utilisation, or from 1 December. Taxmann’s analysis flags the question and no circular has answered it. The practical answer is to reverse on time, which makes the argument irrelevant.

Finding the exposed invoices

This is the step most firms do badly, because the statement they rely on does not carry the information.

GSTR-2B does not show supplier GSTR-3B status. 2B is built from the supplier’s GSTR-1, GSTR-1A, IFF, GSTR-5 and GSTR-6 filings and ICEGATE data, and it is a static statement generated on the 14th (GST portal FAQ). An invoice being in 2B means the supplier reported it, nothing more.

GSTR-2A does. The 2A download carries, against each document, the period and date of the supplier’s GSTR-1 or IFF filing and a GSTR-3B filing status, shown as Yes or No. The column layout is visible in the GSTR-2A format published by the Chhattisgarh GST department. Because 2A is dynamic, a download taken in the first week of October reflects the supplier’s position at the 30 September test date closely enough for a working paper; record the download date.

The portal’s Search Taxpayer tool shows any GSTIN’s return filing table. It is fine for checking three suppliers. It is not fine for three hundred.

A GSP API returns filing status per GSTIN per period in bulk, with the taxpayer’s consent. For a CA office with many clients, this is the only way to run the check monthly rather than annually.

The procedure for FY 2025-26:

1. List every supplier GSTIN from which ITC was availed between April 2025 and March 2026, with the tax periods in which they reported your invoices.
2. For each supplier and period, pull GSTR-3B filing status as of 30 September 2026.
3. Where status is No, total the ITC you availed on that supplier’s documents for that period. That is the exposure.
4. Separate suppliers whose registration has been cancelled; their 3B may never come, and the reversal is permanent in practice.
5. Reconcile the list to what you have already placed on hold under the in-books-not-in-2B bucket of your monthly 2B reconciliation. Invoices you never claimed need no reversal.

GSTN ran this computation itself once: an advisory of 14 November 2023 said the Rule 37A amount for FY 2022-23 had been computed by the system and emailed to recipients, to be reversed in Table 4(B)(2) before 30 November 2023. Lakshmikumaran and Sridharan pointed out the advisory left open which data, 2A or 2B, and which period GSTN had used. We have not found a comparable advisory for FY 2023-24, FY 2024-25 or FY 2025-26 as of October 2026. Do not wait for an email.

Reversing, then re-availing

The Electronic Credit Reversal and Re-claimed Statement, live since August 2023, records every 4(B)(2) reversal and every 4(D)(1) re-claim and triggers a warning when a re-claim exceeds the tracked balance (Taxo). Keep your own supplier-wise register that reconciles to it, because the statement shows totals, not which supplier’s credit is sitting in it.

One more date to hold in mind: Section 16(4) also closes the window for claiming any FY 2025-26 ITC at the GSTR-3B for October 2026, filed by 30 November 2026. The same return in which you reverse Rule 37A credit is the last one in which you can claim anything you missed for the year. Prepare both lists together.

A tracking workflow that does not wait for October

Monthly, after the 14th. Alongside the 2B match, pull GSTR-3B filing status for every supplier in that month’s 2B. Flag suppliers who have filed GSTR-1 but not the previous month’s 3B. This is also the moment to decide IMS actions; our IMS guide covers keeping an invoice pending while a supplier’s filing is in doubt.

Monthly, on payment. For flagged suppliers, hold the GST component of the payment until their 3B shows as filed, where the contract allows it. Many vendor agreements now carry a clause for this; if the client’s do not, add one at the next renewal.

Quarterly. Produce a Rule 37A exposure report per client: supplier, period, ITC amount, filing status, days outstanding, last reminder sent. Send reminders to the suppliers in the client’s name.

First week of October. Freeze the list as of 30 September. Confirm each No with a fresh status pull. Agree the reversal amount with the client, in writing.

October GSTR-3B (or the July to September QRMP return). Reverse in 4(B)(2). Update the supplier-wise register.

Every month after. Re-check the frozen list. When a supplier files, re-avail in 4(A)(5) and 4(D)(1) in the next return and close the register entry.

Year end. Reconcile the register to the Electronic Credit Reversal and Re-claimed Statement before GSTR-9.

What to automate

• Supplier filing-status pulls for every GSTIN in each month’s 2B, through a GSP with the client’s consent, so exposure is known on the 15th and not in October.
• An ITC-on-hold ledger that moves credit out of the safe-to-claim figure the moment a supplier’s 3B is missing, and back when it is filed.
• Supplier reminders naming the invoice, the period and the missing return, with escalation.
• The 30 September freeze and reversal working paper, generated per client with the 4(B)(2) figure and evidence attached.
• Re-availment tracking that watches frozen suppliers and drafts the 4(A)(5) and 4(D)(1) entries when they file.

These steps are part of the reconciliation pipeline our accounting automation service builds for CA firms, and the on-hold and safe-to-claim computation is visible on sample data in the accounting demo. Rule 37A is a rule about your supplier’s behaviour. The only defence is knowing that behaviour every month, not once a year.