Rule 37 can turn an otherwise eligible input tax credit into a temporary reversal when the recipient does not pay the supplier within 180 days from the invoice date. The control therefore belongs in the accounts-payable ledger as well as the GST working. GSTR-2B can show the invoice, but it cannot tell the tax team whether the supplier has been paid.
For a normal forward-charge inward supply, track payment of the invoice value together with the GST charged. If any part remains unpaid at the end of the 180-day period, the current rule requires a proportionate amount of ITC to be paid or reversed, with the applicable interest, in the GSTR-3B for the tax period immediately following that period. The credit may be re-availed after the outstanding value and tax are subsequently paid, provided the underlying ITC remains eligible.
The legal trigger in one line
The current CBIC text of Rule 37 links four facts: ITC was availed, the inward supply is not under reverse charge, the supplier was not paid the value plus tax within the section 16(2) period, and the relevant credit must be dealt with in the return immediately following the 180-day period. Notification No. 19/2022-Central Tax substituted this return-based mechanism from 1 October 2022.
Notification No. 26/2022-Central Tax then made the partial-payment treatment explicit with effect from the same date. It inserted “whether wholly or partly” and requires reversal proportionate to the amount not paid. That wording is why a partly paid invoice should not be converted automatically into a full-credit reversal.
Worked ledger: a partial payment and later reclaim
| Item | Amount | Rule 37 treatment in this example |
|---|---|---|
| Taxable value | ₹1,00,000 | Part of the amount required to be paid to the supplier. |
| GST charged and ITC availed | ₹18,000 | Original eligible credit, assumed to have been validly claimed. |
| Total invoice amount | ₹1,18,000 | Base for measuring the paid and unpaid proportions in this illustration. |
| Paid by the end of 180 days | ₹70,800 | 60% of the invoice has been paid. |
| Still unpaid | ₹47,200 | 40% remains unpaid. |
| Proportionate ITC | ₹7,200 | ₹18,000 × 40%; this is the Rule 37 amount to be paid or reversed, subject to the actual invoice and payment mapping. |
If the remaining ₹47,200 is paid later, the ₹7,200 may be considered for re-availment under Rule 37(2). The file should connect the original claim, temporary reversal, bank payment and reclaim. The example assumes the payment relates proportionately to the invoice as a whole; unusual settlements, set-offs or disputed amounts need their own documented analysis.
Build the 180-day control from invoices, not vendor totals
A vendor-level closing balance is not enough. One supplier may have ten invoices: six fully paid, two partly paid and two still within the 180-day window. Netting the account can hide which credit is exposed. The working should retain at least these fields:
| Field | Why it is needed |
|---|---|
| GSTIN, invoice number and invoice date | Identifies the inward supply and starts the invoice-specific 180-day clock. |
| Taxable value and tax by head | Supports the original ITC and the amount available for proportionate calculation. |
| ITC actually availed and tax period | Prevents the team from reversing credit that was never claimed. |
| Payment date and amount mapped to the invoice | Establishes the paid percentage at the relevant cut-off. |
| 180-day cut-off and following return period | Routes the item into the correct GSTR-3B working instead of an arbitrary month-end bucket. |
| Reversal, interest review and reclaim references | Creates a complete trail until the item is closed. |
The date control should be generated from the supplier invoice date, not the posting date, GRN date or date on which the invoice appeared in GSTR-2B. Keep the calculation rule consistent and review invoices that sit close to a return-period boundary before filing.
What goes into GSTR-3B?
Rule 37 describes the amount as payable or reversible while furnishing GSTR-3B. The current GST Portal GSTR-3B manual treats reclaimable reversals through Table 4(B)(2). When the condition is later fulfilled, the reclaimed ITC is reported in Table 4(A)(5), with the reclaim disclosure in Table 4(D)(1). The Electronic Credit Reversal and Re-claimed Statement tracks the running position.
This is a temporary-credit workflow, not a finding that the purchase itself is permanently ineligible. Permanent reversals belong in a different part of Table 4. The return preparer should therefore tag the Rule 37 item as reclaimable and keep it open until supplier payment supports a reclaim or another fact closes the item.
Interest needs a separate, current-law sign-off
Rule 37 expressly refers to interest under section 50. Do not treat the adjustment as a bookkeeping transfer with no interest review. At the same time, do not hard-code an old rate or a blanket computation into the article or ERP rule. The applicable section 50 and Rule 88B position, utilisation facts, period and portal computation should be checked for the specific return before filing.
A practical control is to give the tax reviewer three separate columns: ITC to be reversed, interest conclusion, and interest amount. That prevents a valid reversal calculation from being mistaken for a completed interest analysis.
Items that should not enter the ordinary Rule 37 queue
- Reverse-charge supplies: Rule 37(1) excludes supplies on which tax is payable under reverse charge. CBIC's reverse-charge FAQ also states that the 180-day consideration condition does not apply in that case.
- Schedule I supplies without consideration: the rule deems their value to have been paid for this purpose.
- Amounts added under section 15(2)(b): Rule 37 contains a separate deemed-payment provision for those additions.
- Invoices on which ITC was not availed: an unpaid invoice may be an AP issue, but there is no Rule 37 credit to reverse until credit has actually been taken.
These exclusions should be rule-based flags in the working rather than manual deletions. That makes it possible to explain why an aged invoice was excluded when the file is reviewed later.
Rule 37 and Rule 37A are different failure points
| Question | Rule 37 | Rule 37A |
|---|---|---|
| Whose action creates the issue? | The recipient has not paid the supplier within the prescribed period. | The supplier reported the document but did not furnish the corresponding GSTR-3B within the rule's timeline. |
| Primary evidence | Invoice-level payment ledger and bank trail. | Supplier-return status and the statutory dates for the relevant financial year. |
| Can full supplier payment solve it? | Payment can support re-availment under Rule 37(2). | No; the supplier must subsequently furnish the relevant GSTR-3B. |
Notification No. 26/2022 inserted Rule 37A while also amending Rule 37. Keeping the two rules in separate exception queues avoids a common reconciliation error. For the supplier-filing workflow, see the related Rule 37A guide.
Month-end close procedure
- Extract only invoices on which ITC has actually been availed and calculate the 180-day cut-off from the invoice date.
- Map bank payments and other supported settlements invoice by invoice; do not allocate a vendor total without an auditable rule.
- Remove reverse-charge and deemed-paid cases with a recorded reason.
- For each unpaid or partly unpaid invoice, calculate the unpaid proportion and apply it separately to the ITC by tax head.
- Route the reclaimable amount to the appropriate GSTR-3B working and obtain a separate interest conclusion.
- Carry the item forward with the original claim and reversal references. On later payment, test re-availment and record the Table 4(A)(5) and 4(D)(1) references.
- Reconcile the final working to the purchase ledger and the broader GSTR-2B versus purchase-register control.
A Rule 37 control is complete only when every flagged invoice has a traceable outcome: excluded with a legal reason, paid within time, proportionately reversed, or reclaimed after payment. Leaving old reversals in a spreadsheet without a payment-linked reclaim field can permanently strand otherwise eligible credit.
