Is IMS Mandatory? What the Law Says, What the Portal Does, and Why Doing Nothing Is an Answer

Ask whether the Invoice Management System is mandatory and you will get both answers, confidently. Both are right, which is the problem.

No section and no rule requires you to touch IMS. There is no obligation to accept, reject or keep anything pending, and no penalty for ignoring the dashboard entirely. GSTN has said so in writing more than once. On 14 October 2024, the day it went live: "it is not mandatory to take action on invoices in IMS dashboard for GSTR-2B generation." A month later, plainer still: "IMS is an optional facility."

And yet ignoring it is not a compliance option. Because of what IMS sits in front of.

The rule that actually binds

Input tax credit has a gate, and it is not in IMS. Rule 36(4)(b) says no credit may be taken unless the details of the credit "have been communicated to the registered person in FORM GSTR-2B under sub-rule (7) of rule 60". Section 16(2)(ba) adds that credit communicated under section 38 must not have been restricted.

So the law's demand is simple: your credit must be in your GSTR-2B. It says nothing about how it gets there.

Since October 2024, the only thing that decides what is in your GSTR-2B is what happened in IMS. Nothing was amended to achieve that. The 55th GST Council recommended amending both section 38 and rule 60 to give IMS a legal frame. Section 38 was amended, from 1 October 2025 — it now says a "statement", where it used to say "an auto-generated statement". Rule 60 was never amended. It still promises an auto-generated statement, every month.

That is the whole answer. The law does not require you to use IMS. The law requires your credit to be in GSTR-2B. IMS decides what is in GSTR-2B. Ignoring it is not abstention; it is letting the portal decide your credit for you.

What doing nothing actually does

Nothing is not neutral. It is a decision, and the portal records it as acceptance:

"If recipient doesn't take any action on an invoice in IMS then it will be deemed accepted and will move to GSTR-2B as an accepted invoice."

GSTN presents this as a kindness, and for a clean supplier ledger it is. Read it the other way round and it is the risk: a duplicate invoice, an invoice on the wrong GSTIN, or an invoice from a supplier you have a dispute with, flows into your GSTR-2B and then into GSTR-3B as eligible credit — because nobody looked. Wrong credit carries interest under section 50 and a demand under section 73 or 74. The safe default is the opposite of the portal's default.

Rejecting wrongly costs too: "rejection will result in no ITC for the recipient."

The three actions, and the one that expires

• Accept — into "ITC Available", and into GSTR-3B as eligible credit.
• Reject — into "ITC Rejected". No credit.
• Pending — in neither, and it stays on the dashboard until you deal with it.

Pending is the useful one, and it is fenced. It cannot be used at all for an original credit note, an upward amendment of a credit note, a downward amendment of a credit note whose original you rejected, or a downward amendment of an invoice you had already accepted and filed. Bills of entry, in IMS since October 2025, cannot be rejected at all.

For ordinary invoices, a pending record survives until the section 16(4) date and is then removed from the dashboard, credit and all. For the credit-note records that became pendable from the October 2025 tax period, the fuse is far shorter: one tax period, after which "Pending action will be disabled … If no action is taken then system will consider such record as deemed accepted."

When GSTR-2B appears, and when it does not

The draft arrives on the 14th, automatically. GSTN reaffirmed this in October 2025, against a wave of claims that it had changed: "GSTR-2B will continue to be generated automatically on the 14th of every month, without any manual intervention."

Two cases where it will not appear, and both catch people:

• Quarterly filers under QRMP get no GSTR-2B for the first and second months of a quarter.
• If your previous period's GSTR-3B is unfiled, no GSTR-2B is generated at all. File the pending return, then press Compute GSTR-2B on the IMS dashboard.

And one that catches everyone: act after the 14th and you must recompute. "It is mandatory to recompute GSTR 2B from IMS dashboard in case of any change in action already taken … or any action is taken after 14th of the month." Skip it and the return carries the figures from before you acted. Once GSTR-3B is filed, the actions freeze for that period.

Credit notes, where your action moves someone else's money

From 1 October 2025 the proviso to section 34(2) says a supplier gets no reduction in output tax "if the input tax credit as is attributable to such a credit note, if availed, has not been reversed by the recipient".

IMS is how that is enforced. Reject a credit note and the supplier's liability goes up — in the next tax period's GSTR-3B, not the same one. Accept it and you are asked whether credit needs to be reduced: no, if you never took it; partly, if you took part of it. Where the reversal is partial or nil, remarks are mandatory.

This is the one place where an IMS action is not merely your own affair. Your click changes a counterparty's return.

What is locked, and what is not

The liability side of GSTR-3B is locked. From the July 2025 tax period, the figures auto-populated from GSTR-1, GSTR-1A and IFF cannot be edited; the only route to a correction is GSTR-1A for the same period, filed before GSTR-3B.

The credit side is not. As at 27 September 2026 GSTN has issued no advisory locking Table 4 ITC, though one was promised "at a later date" back in October 2024. Claims that Table 4A was hard-locked from January, April or July 2026, or that the portal now blocks a GSTR-3B where the credit claimed exceeds GSTR-2B, rest on no notification and no advisory that we could find. What does exist is rule 88D and FORM DRC-01C: an intimation asking you to explain or reverse an excess, which is not the same thing as a block. For the detail of what is locked, see what is locked in GSTR-3B and IMS.

For the same reason, treat "IMS became mandatory on 1 April 2026" as what it is: widely repeated, and attached to no notification, rule or advisory.

The date that ends the argument

For FY 2025-26, section 16(4) gives credit until 30 November 2026, or the date the annual return is filed, whichever is earlier. In practice the last return that can carry it is the GSTR-3B for October 2026.

A record left pending past that date is dropped from the dashboard and the credit dies with it. That is the deadline to run the dashboard against, and it is the one argument about whether IMS is mandatory that has an answer in money.

IMS is optional in the way that reading your bank statement is optional. Nothing compels it. Everything downstream assumes you did.

Where this comes from

The Central Goods and Services Tax Act, 2017, sections 16(2)(aa), 16(2)(ba), 16(4), 34(2) and 38, and rules 36(4)(b) and 60(7) and (8) of the CGST Rules; section 38 and the proviso to section 34(2) as amended from 1 October 2025 by the Finance Act, 2025. The IMS positions are GSTN's own, quoted from its advisories and FAQs of 22 September, 14 October, 17 October, 12 November and 16 November 2024; 7 June, 23 September, 8 October, 15 October and 30 October 2025; and 23 April 2026, which introduced the offline tool for acting on invoices in bulk. Where a widely-reported change has no primary document behind it, this page says so rather than repeating it.