Rule 37A sheet for CA firms: which supplier invoices each GST client must reverse ITC on by 30 November 2026 (supplier GSTR-3B not filed for FY 2025-26)

Updated 23 Oct 2026 · Disclosure: the white-label calendar linked below is an Unadhi product (₹999/year).

What you get: a ready-to-copy Google Sheet layout with one row per supplier invoice or debit note on which a GST client took input tax credit in FY 2025-26. By formula it tells you, for each row, "No reversal", "Check supplier", "Reverse in 4(B)(2) by 30 Nov 2026", "Reversed" or "Re-avail in 4(A)(5) + 4(D)(1)", with the tax heads split and days left to 30 November. Plus three made-up example rows, a plan to 30 November and a supplier message. Free, no sign-up.

Short answer (checked 23 Oct 2026): under rule 37A of the CGST Rules, 2017 (CBIC), if a client took ITC in GSTR-3B on an invoice or debit note that the supplier reported in GSTR-1 (as amended in GSTR-1A, if any) or the IFF, but the supplier has not furnished its GSTR-3B for that tax period by 30 September after the end of the financial year in which the client took the credit, the client must reverse that ITC in a GSTR-3B filed on or before 30 November of that year. For credit taken in FY 2025-26 the dates are 30 September 2026 (supplier test, already passed) and Monday 30 November 2026 (client reversal). If not reversed by then, the amount is payable with interest under section 50. If the supplier files that GSTR-3B later, the client may re-avail the credit in a later GSTR-3B. This is a starting point, not tax advice.

Why this needs a list now

• The supplier test date has passed. 30 September 2026 is gone, so for FY 2025-26 credit the only question left is which suppliers had not filed GSTR-3B by then, and how much credit your client took on their invoices.
• The year is the year of availment. Rule 37A looks at "the end of financial year in which the input tax credit ... has been availed". Key each row on the GSTR-3B period in which your client took the credit, not the invoice date.
• Late reversal costs interest. The first proviso: ITC not reversed in a GSTR-3B on or before 30 November is payable "along with interest thereon under section 50". See our section 50 interest guide; this page does not state a rate.
• Do not wait for an email. For FY 2022-23, a GST Council note says the rule 37A amount was computed by the system and emailed to the registered email of recipients, with advice to reverse in Table 4(B)(2) of GSTR-3B before 30.11.2023 (GST Council, "Recent amendment in GST in October 2023"). The legal duty is in the rule, whether or not an email arrives. Use your own working.

Where it goes in GSTR-3B

• Reversal: CBIC Circular No. 170/02/2022-GST (6 July 2022) puts reversals that are "not permanent in nature and can be reclaimed in future", such as rule 37 and section 16(2)(c), in Table 4(B)(2). The FY 2022-23 note above names Table 4(B)(2) for rule 37A.
• Re-availment: the same circular says such ITC "may be reclaimed in Table 4(A)(5)" and all reclaimed ITC "shall also be shown in Table 4(D)(1)".
• The reclaim ledger tracks it. GSTN's note on the Electronic Credit Reversal and Re-claimed Statement says the statement tracks ITC reversed in 4(B)(2) and re-claimed in 4(D)(1) and 4(A)(5), and warns if you reclaim more than the balance plus this period's 4(B)(2) reversal. Reverse in 4(B)(2) so that a later reclaim has a balance to come from.

Tab "37A": one row per supplier invoice or debit note

On a "Clients" tab, total column M per client where Q starts with "Reverse": =SUMIFS('37A'!M:M,'37A'!A:A,A2,'37A'!Q:Q,"Reverse*"). That is the figure for the client's 4(B)(2) entry, split by head with the same SUMIFS on G to J.

The rule text applies where the supplier's GSTR-3B for the period "has not been furnished". If the supplier tells you it filed late but before 30 September, ask for the filing proof and record it in L.

Three made-up example rows

All names and amounts are made up for illustration.

Plan to 30 November

Supplier message

"Our records show your invoice [number, date] in your GSTR-1 for [month], on which [client] took input tax credit. Please confirm that your GSTR-3B for [month] was filed, and send the filing acknowledgement. Under rule 37A of the CGST Rules we must otherwise reverse this credit by 30 November 2026."

Notes

• The words "as amended in FORM GSTR-1A if any" were inserted by Notification No. 12/2024-CT dated 10.07.2024 (CBIC rule page). Use the supplier's amended figures where a GSTR-1A exists.
• Rule 37 (supplier not paid within 180 days) is a different reversal with its own conditions; keep it on a separate tab.
• Re-availment is "in the return in FORM GSTR-3B for a tax period thereafter", after the supplier files. Check the section 16(4) time limit separately; see our section 16(4) guide.

Related guides

• IMS invoice action sheet (October 2026)
• GSTR-3B chase list before the 20th
• GSTR-9 / 9C FY 2025-26 chase list
• November 2026 due-date chase list

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