Table 3.2 is locked. Fix it in GSTR-1A, not in your 3B

Most teams meet this at 11pm on the 20th: the inter-state figure auto-filled into Table 3.2 is wrong, the field will not accept a keystroke, and GSTR-3B is due. The correction exists, but it lives one form upstream and it has to be made before you file the 3B — not after. Here is the sequence, with numbers.

What changed, and exactly when

GSTR-3B is being frozen table by table, not all at once. The dates are different for each block, and conflating them is the most common error in circulation.

Two things worth pinning down, because both are widely misreported:

• Table 3.2 did not actually lock in July 2025 — though GSTN twice said it would. Non-editability of 3.2 was first announced for the April 2025 period (advisory of 11 April 2025), deferred after representations, and announced again for the July 2025 period (advisory of 19 July 2025). Neither stuck. The operative instrument is the GSTN advisory of 5 December 2025, which makes Table 3.2 non-editable "from November-2025 tax period onwards". What did take effect from the July 2025 period is the separate lock on the auto-populated outward liability in Tables 3.1 / 3.1.1, under the advisory of 7 June 2025. If you are working from a checklist written in mid-2025, it is describing an instrument that was superseded.
• The ITC side is not locked. No GSTN instrument has ever fixed a date for Table 4. The only instrument on record — the advisory of 17 October 2024 — says ITC locking "will be implemented from a later date", subject to a separate advisory that has not issued. If you have read that Table 4 locks from the July 2026 period, that date comes from secondary media, not from GSTN.

What Table 3.2 actually holds

Table 3.2 is not a second liability figure. It is a breakup. GSTN's own description: Table 3.2 "captures the inter-state supplies made to unregistered persons, composition taxpayers, and UIN holders out of the total supplies declared in Table 3.1 & 3.1.1 of GSTR-3B", split by place of supply. It is auto-populated from the corresponding tables of your GSTR-1, GSTR-1A and IFF — for most filers that means the state-wise B2C summary (Table 7B of GSTR-1), the invoice-wise inter-state B2C-large table (Table 5), the B2B table where the customer is a composition dealer or UIN holder, and the amendment tables that revise any of them.

Because it is a subset, it has a property that trips people up: it never changes your tax payable. The IGST is already in 3.1(a). Table 3.2 only says which state that IGST belongs to. This is why the error is so easy to miss for months — nothing in your cash ledger, your books or your payment challan reacts to a wrong 3.2. The figure is wrong, the tax is right, and no internal control fires.

It is not consequence-free at the other end, though. Section 17 of the IGST Act apportions integrated tax on precisely these categories — supplies to unregistered persons and to composition taxable persons — to the State of the place of supply. The state-wise split you report is the input to that settlement, which is why GSTN has an interest in taking the pen out of your hand.

Where the wrong number usually comes from

Table 3.2 is auto-populated from your GSTR-1. So a wrong 3.2 is always a wrong GSTR-1 — the 3B is just showing it to you. In practice the cause is one of four:

• Place of supply keyed to the billing address instead of the ship-to state. The single most common one, and it survives review because the invoice total is correct.
• A B2C-large invoice reported without its state-wise split, or in the wrong state's row.
• A credit note issued against an inter-state B2C supply landing in a different state's bucket from the original invoice.
• Registration status misjudged — the customer was actually unregistered (or composition), so the supply belonged in the 3.2 breakup and never got there. Note the limit on the fix: GSTR-1A can amend the invoice, but it cannot amend a recipient's GSTIN (GSTN FAQ). If the error is that you reported a B2C supply against a wrong GSTIN, that one has to go through the amendment tables of a later GSTR-1.

The fix: GSTR-1A, same period, before the 3B

GSTR-1A is an amendment facility that lets you correct or add to a GSTR-1 you have already filed, for the same tax period, before you file that period's GSTR-3B. It was brought in by Notification 12/2024-Central Tax dated 10 July 2024 (amending Rule 59 and inserting Form GSTR-1A) and went live on the portal in August 2024, first usable for the July 2024 period. The window is precise, and GSTN states it: GSTR-1A opens on the later of the GSTR-1 due date (the 11th) or the date you actually file GSTR-1, and closes the moment you file GSTR-3B for that period. There is no separate due date. The order is the whole point. Once GSTR-3B is filed for the period, the same-period window is gone, and the correction has to travel through the ordinary amendment tables in a later month's GSTR-1 instead.

So the month-end sequence is now fixed:

1. File GSTR-1.
2. Open the auto-drafted GSTR-3B and read Table 3.2 before doing anything else. This is the check, and it takes two minutes.
3. If 3.2 is wrong, file GSTR-1A for the same period with the corrected place-of-supply lines.
4. Refresh the GSTR-3B. The amended figures flow through.
5. File GSTR-3B.

Step 2 is the one that is missing from most close checklists. Teams review GSTR-1 before filing it — but almost nobody reviews the auto-drafted 3B before filing, because for Table 3.2 there was no need to until the November 2025 period: you could just fix the number in the field.

A worked example

A Gurugram-registered distributor sells to unregistered customers in three states in November 2025. Total inter-state B2C supplies of ₹40,00,000, IGST at 18% = ₹7,20,000. The GSTR-1 carries a place-of-supply error: a ₹9,00,000 batch of orders shipped to Rajasthan was keyed to the customer's Delhi billing address.

Note the last row. The total is identical, the IGST payable is identical, Table 3.1(a) is correct, and the cash ledger is unaffected. ₹1,62,000 of IGST is simply attributed to the wrong state. Before November 2025 the filer would have retyped the two rows in Table 3.2 and moved on. From the November 2025 period the fields are dead: the only route is a GSTR-1A restating the Rajasthan lines, filed before the 3B.

If you miss the window

Nothing catastrophic happens on the day — which is precisely the risk, because it means the error compounds quietly. Two consequences are worth planning for:

• The correction slips to a later return. With the same-period window closed, you amend in a subsequent GSTR-1, which leaves your filed 3.2 for the month permanently at odds with your sales register. Annual reconciliation then has to carry and explain the difference.
• Credit notes have a hard outer limit. Where the correction runs through a credit note, Section 34(2) of the CGST Act requires it to be declared no later than 30 November following the end of the financial year in which the supply was made, or the date of furnishing that year's annual return, whichever is earlier — so filing GSTR-9 early closes the window early. And no reduction in output tax is permitted unless the recipient, if registered, has reversed the ITC attributable to that credit note (or, in other cases, the incidence of tax has not been passed on). After that, the route is closed entirely.

Separately, keep in mind that GSTR-1 filing is sequential: under Rule 59(6)(a) you cannot furnish GSTR-1 for a month if the GSTR-3B for the preceding month has not been filed (for QRMP filers, the preceding quarter's return) — and clauses (d) and (e) of the same sub-rule block GSTR-1 or the IFF for a subsequent period where a Rule 88C or Rule 88D intimation has gone unpaid and unanswered. A month you left unresolved does not stay contained to that month.

What a controller should change this quarter

Three concrete edits to the close checklist:

1. Add a pre-filing read of the auto-drafted GSTR-3B. Between filing GSTR-1 and filing 3B, someone reads Tables 3.1, 3.1.1 and 3.2 against the sales register. That gate is the entire defence.
2. Reconcile place of supply at the invoice, not the customer. The failing control is almost always a master-data one: place of supply inherited from a customer record rather than derived from the delivery on that invoice.
3. Treat GSTR-1A as a routine step, not an exception. If the pre-filing read finds a difference, the fix is a same-period GSTR-1A — budget the time for it inside the filing window rather than treating it as an escalation.

Where Recoup fits

Recoup works the credit side of this chain: it reconciles your Zoho Books ITC against your GSTR-2B continuously, names the vendor behind every gap, and tracks the Rule 37 180-day clock — so the numbers you file are checked before you file, not after. The discipline Table 3.2 now forces on the outward side is the same one Rule 88D already forces on the inward side: know your figures before the return, because the return is no longer the place you get to fix them.

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