Is Table 4A of GSTR-3B locked from July 2026? Not as of September 2026. Many articles describe a "Phase 2" hard lock of ITC in Table 4 of GSTR-3B from July 2026, but GSTN has not issued an advisory notifying it. What is locked today is the outward liability side: Table 3 from the July 2025 tax period and the Table 3.2 inter-state breakup from the November 2025 tax period. ITC in Table 4 is auto-populated from GSTR-2B but remains editable, and over-claims are policed through Rule 88D (DRC-01C).
The confusion is understandable. GSTN has been moving GSTR-3B step by step towards a system-generated return, and the next logical step is the ITC side. But a planned or reported change is not the law until the portal advisory or a CBIC notification says so. This guide separates what is in force from what is only expected, and sets out a monthly routine that keeps you safe either way.
What Is Actually Locked in GSTR-3B Today
Table 3: Outward Liability (from the July 2025 tax period)
GSTN first announced hard-locking of auto-populated liability in an advisory of October 2024, deferred it in January 2025, and brought it into force from the July 2025 tax period (returns filed from August 2025). The tax liability in Table 3 is auto-populated from GSTR-1, GSTR-1A and IFF and cannot be edited in GSTR-3B. If a figure is wrong, you correct it through GSTR-1A for the same period before filing GSTR-3B; the change flows into GSTR-3B immediately.
Table 3.2: Inter-State Supplies Breakup (from the November 2025 tax period)
By an advisory dated 5 December 2025, GSTN made the auto-populated values in Table 3.2 (inter-state supplies to unregistered persons, composition taxpayers and UIN holders) non-editable from the November 2025 tax period. Corrections again go through GSTR-1A.
Table 4: ITC (auto-populated, still editable)
ITC in Table 4 is auto-populated from GSTR-2B, but as of September 2026 no GSTN advisory has made it non-editable. You can still change the figures. That does not mean you can claim freely: under Section 16(2)(aa) and Rule 36(4), ITC is available only on invoices that appear in GSTR-2B, and if the ITC you claim exceeds GSTR-2B beyond the notified threshold, the portal issues a DRC-01C intimation under Rule 88D.
Which Table 4 Rows Come From GSTR-2B
Understanding the source of each row matters because it tells you where the portal has data and where it depends entirely on you.
| Row | What it reports | Source today |
|---|---|---|
| 4A(1) | Import of goods | Auto-populated from GSTR-2B (ICEGATE Bill of Entry data); editable |
| 4A(2) | Import of services | Your own records; not in GSTR-2B |
| 4A(3) | Inward supplies liable to reverse charge (other than 4A(1) and 4A(2)) | RCM from registered suppliers auto-populated from GSTR-2B; RCM on purchases from unregistered persons is your own entry |
| 4A(4) | Inward supplies from ISD | Auto-populated from GSTR-2B; editable |
| 4A(5) | All other ITC (regular B2B purchases) | Auto-populated from GSTR-2B; editable |
| 4B(1) | Reversals under Rules 38, 42 and 43 and Section 17(5) (permanent) | Your own computation; GSTR-2B shows some ineligible ITC |
| 4B(2) | Other reversals, including amounts you may reclaim later (for example, supplier not paid within 180 days) | Your own computation |
| 4C | Net ITC available (4A minus 4B) | System computed |
| 4D(1) | ITC reclaimed that was reversed under 4B(2) in an earlier period | Your own entry (the credit itself is reclaimed through 4A(5)) |
| 4D(2) | Ineligible ITC under Section 16(4) and ITC restricted by place-of-supply rules | Auto-populated from GSTR-2B where available; editable |
Note that regular B2B credit sits in 4A(5), not 4A(1). Row 4A(1) is only for IGST on imports of goods. This row structure has applied since the Table 4 changes notified in July 2022 (Notification 14/2022-Central Tax, explained in Circular 170/02/2022-GST).
IMS and the 14th: How ITC Reaches GSTR-3B
The Invoice Management System went live on the GST portal from 1 October 2024. The flow is:
- Your supplier files GSTR-1 (due 11th for monthly filers) or uploads invoices in IFF (1st to 13th for QRMP filers)
- The invoice appears in your IMS dashboard
- You accept, reject or keep it pending; any record left without action is deemed accepted
- GSTR-2B is generated on the 14th, with accepted and deemed-accepted records as ITC available
- GSTR-3B Table 4 is auto-populated from GSTR-2B
- You review, adjust where your records justify it, add reversals, and file GSTR-3B by the 20th (monthly filers)
Accept, Reject or Pending
Accept: the record flows into GSTR-2B as ITC available.
Reject: the record is excluded from GSTR-2B. Use this for invoices that are duplicates, belong to someone else or relate to supplies you never received. A rejected invoice does not come back by itself; it reappears only if the supplier re-reports or amends it.
Pending: the record is held out of the current GSTR-2B and carried forward, within the time limit for claiming that credit.
No action: treated as accepted when GSTR-2B is generated. This is the biggest operational risk. If a supplier uploads a wrong or bogus invoice against your GSTIN and you do not act, the credit shows up in your auto-populated Table 4.
The 14th Is a Planning Date, Not a Hard Cut-Off
GSTR-2B is generated on the 14th, but you can still change IMS actions after that and recompute GSTR-2B, as long as you have not filed GSTR-3B for the period. Once GSTR-3B is filed, actions for that period are frozen. In practice, finishing IMS review before the 14th gives you a clean GSTR-2B and a week to prepare GSTR-3B.
What Happens When ITC Is Missing
Supplier Has Not Filed GSTR-1
The invoice will not appear in your IMS or GSTR-2B. Follow up with the supplier, and claim the credit in the month it appears in your GSTR-2B. Under Section 16(4), ITC for a financial year must be claimed by 30 November of the following financial year or the date of filing the annual return, whichever is earlier.
Invoice Amount Mismatch
GSTR-2B reflects the supplier's figures, not yours. If the supplier's amount is lower, you can claim only what is in GSTR-2B until the supplier amends it. If the supplier's amount is wrong and higher, reject the record in IMS and ask the supplier to re-report the correct figure; do not claim credit you are not entitled to.
Credit Note Not Reported
If the supplier has issued a credit note but not reported it, your GSTR-2B still shows the full original credit. Track credit notes in your books and reverse the excess through Table 4B so your claim matches the actual tax charged.
Impact on Different Business Types
Regular Monthly Filers
The cycle repeats monthly: IMS review before the 14th, GSTR-2B on the 14th, GSTR-3B by the 20th. That leaves about six days to reconcile, compute reversals and file.
QRMP Filers
Under the QRMP scheme, GSTR-2B is generated for the quarter and GSTR-3B is filed quarterly (by the 22nd or 24th of the month after the quarter, depending on your state), with tax paid monthly through PMT-06 by the 25th. IMS records accumulate over three months, so the review is larger even though the window is wider.
Exporters and SEZ Suppliers
For refunds on zero-rated supplies, the ITC used in the refund computation should be ITC you were entitled to, which since 1 January 2022 means credit reflected in GSTR-2B. Inflated Table 4 figures that GSTR-2B does not support are a common reason for refund deficiency memos and for DRC-01C intimations.
Composition Taxpayers
Composition taxpayers do not file GSTR-3B. They pay tax quarterly through CMP-08 and file an annual GSTR-4. Section 10(4) bars them from claiming ITC, so Table 4 questions do not arise.
Monthly Calendar for a Monthly Filer
| Day | Action | Who |
|---|---|---|
| 1st to 11th | Suppliers file GSTR-1 (due 11th); IMS fills up as they file | Suppliers |
| Through the month, finish by 13th | Review IMS: accept genuine invoices, reject wrong ones, keep doubtful ones pending, chase missing invoices | Your accounts team |
| 14th | GSTR-2B generated by the portal | System |
| 14th to 15th | Download GSTR-2B and reconcile with the purchase register | Your accounts team |
| 15th to 18th | Compute Table 4B reversals (Rules 38, 42, 43, Section 17(5), 180-day rule); recompute GSTR-2B if IMS actions changed | Your accountant |
| 18th to 19th | Review the GSTR-3B draft (auto-populated plus manual rows) against books | Your accountant |
| 20th | File GSTR-3B and pay tax | Filing team |
Reconciliation Is Your Real Control
With or without a future lock, the law already ties your ITC to GSTR-2B. If your books show Rs 5 lakh of ITC and GSTR-2B shows Rs 4.5 lakh, the Rs 50,000 gap cannot be claimed until the supplier's invoices reach your GSTR-2B. Claiming it anyway risks a DRC-01C intimation, interest at 18% under Section 50(3) if excess credit is availed and utilised (rate notified by Notification 13/2017-Central Tax as amended by Notification 9/2022-Central Tax), and a demand under Section 73 or 74.
A Practical Reconciliation Workflow
- On the 14th: download GSTR-2B in Excel or JSON
- Match against the purchase register invoice by invoice. Flag invoices in your books missing from GSTR-2B (supplier not filed) and invoices in GSTR-2B not in your books (possible misuse of your GSTIN or wrong GSTIN by the supplier)
- Split the gap into supplier filing delays (these self-correct) and genuine errors (amendment or reversal needed)
- For delays: write to the supplier and keep a supplier compliance tracker
- For errors: ask the supplier to amend; reject wrong records in IMS before filing GSTR-3B; if credit was already claimed wrongly, reverse it
- Keep your workpaper: it is your evidence if a DRC-01C, ASMT-10 or audit query comes later
Common Mistakes to Avoid
Ignoring IMS. IMS actions are not compulsory, but inaction means deemed acceptance, so wrong invoices flow straight into your auto-populated ITC.
Rejecting genuine invoices in a hurry. A rejected invoice drops out of GSTR-2B and does not return unless the supplier re-reports it. Use "pending" when in doubt.
Ignoring credit notes. GSTR-2B nets off credit notes the supplier has reported. Unreported credit notes leave your credit overstated.
Skipping Table 4B. Reversals under Rules 42 and 43, Section 17(5) and the 180-day rule are your responsibility. The portal has no data to validate them, so errors surface in scrutiny or audit.
Where GSTR-3B Is Heading
The verified sequence so far:
- 1 October 2024: IMS goes live
- July 2025 tax period: Table 3 liability auto-populated from GSTR-1/1A/IFF and made non-editable
- November 2025 tax period: Table 3.2 values made non-editable
- Not yet notified: locking of ITC in Table 4. Industry commentary expects it, but no GSTN advisory fixes a date. Our older April 2026 action plan covers the same ground; check the GST portal's News and Updates for the current position before changing your filing process.
Treat any claim that "Table 4A is locked" as unconfirmed until you see the advisory on gst.gov.in. The routine above works whether or not the lock arrives.
What Your Accounts Team Should Do Now
- Review IMS through the month, not only on the 13th. Flag unfamiliar suppliers immediately.
- Set an internal deadline of the 12th for IMS actions, leaving two days for supplier follow-up before GSTR-2B generation.
- Keep a supplier compliance tracker of who files GSTR-1 on time; link payment terms to timely filing for habitual late filers.
- Reconcile on the 14th, not the 19th.
- Compute Table 4B carefully. Reversals under Section 17(5) and Rules 42 and 43 remain manual and auditable.
- Get help if bandwidth is short. If your team cannot run IMS checks and monthly GSTR-2B reconciliation, a managed GST compliance plan can do it systematically.
AATO Amendment Window for FY 2025-26
By an advisory dated 1 July 2026, GSTN revised the timeline for amending Aggregate Annual Turnover (AATO) on the portal. For FY 2025-26 the amendment window was 1 July to 31 July 2026, with jurisdictional officers reviewing amended figures from 1 August to 15 August 2026. GSTN also deployed functionality to update AATO automatically as later returns are filed. AATO matters for eligibility under the QRMP scheme (up to Rs 5 crore) and for e-invoicing (above Rs 5 crore in any year from FY 2017-18). Composition eligibility is based on aggregate turnover of the previous year (Rs 1.5 crore for most goods suppliers, Rs 75 lakh in special category states, Rs 50 lakh for service providers).
Based on GSTN advisories on hard-locking of auto-populated liability in GSTR-3B (October 2024, January 2025 and June 2025), the GSTN advisory of 5 December 2025 on Table 3.2, the GSTN advisory of 1 July 2026 on AATO amendment, Section 16 and Section 50 of the CGST Act, 2017, and Rules 36(4) and 88D of the CGST Rules, 2017. As of September 2026, we found no GSTN advisory or CBIC notification locking ITC in Table 4 of GSTR-3B. Check gst.gov.in News and Updates for later changes.
