If you file GST, something changed this month that your CA has been worrying about since last year: from the July 2026 tax period, you can no longer manually edit the input tax credit figures in Table 4 of GSTR-3B. The credit you claim is now whatever auto-populates from GSTR-2B and the actions you take in the Invoice Management System (IMS). If an invoice isn't there, the credit isn't there — and there is no box to type it into anymore.
Tax portals are calling it 'hard-locking'. CA forums are running survival guides. But almost everything written so far is for practitioners, full of section numbers. This is the version for the person who actually runs the business — what changed, what your new monthly routine looks like, and the one habit that makes all of it a non-event.
What locked, and when
| From tax period | What you can no longer edit | Where the number comes from instead |
|---|---|---|
| July 2025 | Table 3 — your outward sales and tax liability | Auto-filled from the GSTR-1 you filed (fix mistakes via GSTR-1A before filing 3B) |
| July 2026 | Table 4 — your input tax credit | Auto-filled from GSTR-2B, shaped by your accept / reject / pending actions in IMS |
The intent is simple: the government wants the credit you claim to match, invoice for invoice, what your suppliers actually reported and paid. The era of claiming ITC on good faith and reconciling later is over.
IMS in plain English
The Invoice Management System is a screen on the GST portal (and an Excel-based offline tool, released July 2026, for doing it in bulk) where every purchase invoice your suppliers report shows up, waiting for you to act on it. For each invoice you have three buttons:
- Accept — 'yes, this purchase is real and correct.' It flows into your GSTR-2B and becomes claimable credit.
- Reject — 'this isn't mine, or it's wrong.' It stays out of your credit, and the supplier sees the rejection and must fix it on their side.
- Pending — 'I'm not sure yet' (goods not received, amount disputed). The invoice waits, and the credit stays parked until you decide in a later period.
Do nothing, and invoices are treated as deemed-accepted when GSTR-2B is generated. That sounds convenient, but it means a wrong invoice slips into your credit — and a missing one simply never appears. Either way, the number in your 3B is now decided before you open the form.
Your new monthly routine
The whole change fits into three dates. Miss them and you are not filing wrong — you are filing blind:
| Date | What happens | What you should do |
|---|---|---|
| 11th | Suppliers' GSTR-1 due — their invoices land in your IMS | Nothing yet; the picture is still filling in |
| 14th | Your GSTR-2B generates from IMS | Before this: review IMS, accept what's real, reject what's wrong, mark disputes pending |
| 20th | Your GSTR-3B due | Confirm the auto-filled figures and file — the editing window is gone |
The real cost: your supplier's late GSTR-1 is now your problem
Here is the part that hits distributors and traders hardest. Say you bought ₹5 lakh of stock in July and paid your supplier, GST included — ₹90,000 of it at 18%. If that supplier files their GSTR-1 late or misses your invoice, that ₹90,000 does not appear in your 2B, and you cannot claim it this month. You pay your full output tax in cash instead, and the credit arrives whenever your supplier gets around to filing. That is working capital — real money — sitting hostage to someone else's compliance.
The practical response: make supplier filing discipline part of how you buy. Prefer suppliers who file on time, chase the ones who don't in the window between the 11th and the 14th (a WhatsApp message with the invoice number works better than a phone call after the 20th), and check your IMS before the 2B generates, not after the credit has already gone missing.
Common mismatches, and what to do about each
- Invoice in your books but not in IMS — the supplier hasn't reported it. Chase them before the 14th; the credit waits until they file.
- Invoice in IMS that isn't yours — reject it. Deemed-accepting someone else's invoice inflates your credit and invites a notice later.
- Amount or GSTIN is wrong — reject it and have the supplier amend in their next GSTR-1; don't accept 'approximately right' invoices anymore.
- Goods not yet received — mark it pending. ITC rules still require receipt of goods; pending parks the credit legitimately until delivery.
- Missed acting before the 2B generated — deemed acceptance applies; review the following month's IMS carefully and correct course there.
If you file quarterly under QRMP, the same logic applies around your quarter's dates — and composition dealers are outside this entirely (no GSTR-3B, no ITC). For a refresher on the other side of this handshake — filing your own sales cleanly so your buyers' credit lands — see our guide to GSTR-1 filing.
One more reason this matters beyond compliance: your buyers now see, invoice by invoice, whether you file on time. A distributor whose retailers' credit lands like clockwork is a distributor retailers prefer to buy from. Clean GST invoicing has quietly become a sales advantage — and if you still run billing on a desktop package that can't keep up, this is the change that will expose it.
Frequently asked questions
Can I still claim ITC that is not showing in GSTR-2B?
No. From the July 2026 tax period, Table 4 of GSTR-3B cannot be edited manually — if the invoice isn't in your GSTR-2B (via your supplier's filing and your IMS actions), the credit cannot be claimed that month. It becomes claimable once the supplier reports it.
What happens if I reject an invoice by mistake in IMS?
The credit stays out of your 2B and the supplier is notified of the rejection. The fix flows through the supplier re-reporting or amending the invoice, after which you can accept it in a later period — so reject carefully, and use 'pending' when you're merely unsure.
Is IMS mandatory?
Acting on invoices is technically optional — anything you don't act on is deemed accepted when GSTR-2B generates. But since deemed acceptance can pull wrong invoices into your credit and hides missing ones, treating IMS review as mandatory is the only safe practice.
What if my supplier files GSTR-1 after the 13th?
Their invoices miss your GSTR-2B for that period, and the ITC becomes available only in the following month's 2B. You pay that month's output tax in cash in the meantime — which is why chasing late-filing suppliers before the 14th is now a monthly discipline.
Does this apply to composition scheme dealers?
No. Composition dealers don't file GSTR-3B or claim ITC, so hard-locking doesn't affect them. It applies to regular taxpayers filing monthly or under QRMP.
Rules like this reward the organised. Keep every purchase recorded the day it happens, check IMS on a fixed day each month, and chase stragglers with the invoice number in hand — and the scariest GST change in years becomes a ten-minute monthly routine.
