GST IMS: Accept, Reject, Pending, and the Monthly Workflow

The Invoice Management System, or IMS, requires a decision, accept, reject or pending, on every invoice, credit note and debit note your suppliers report, before GSTR-2B is generated for the period. Accepted and untouched invoices flow into GSTR-2B and count toward your eligible ITC; rejected invoices are excluded from it; pending invoices simply do not appear in that period's GSTR-2B and carry forward for action later.

IMS changes what used to be a passive process into an active one. Previously, GSTR-2B was generated purely from what suppliers reported, and a recipient's only real lever was whether to claim the ITC in GSTR-3B. IMS inserts a review step before that, and the step matters because doing nothing is not neutral: an invoice left untouched is treated as accepted once GSTR-2B is generated. This guide covers what each of the three actions actually does, the monthly sequence IMS sits inside, and a workflow that keeps this from becoming a last-minute scramble before the return deadline. For the mechanics of the return that IMS feeds into, see the GSTR-2B reconciliation guide.

What IMS is and why it exists

Before IMS, a recipient's GSTR-2B was a fixed snapshot generated automatically from supplier filings, and any dispute about an invoice, whether it was genuinely received or correctly billed, had to be sorted out after the fact, often through communication outside the GST system entirely. IMS puts every reported document in front of the recipient first, on a rolling basis as suppliers file, and asks for a decision before that snapshot is finalised.

The practical effect is that a recipient now has a documented, on-portal record of which invoices they have reviewed and accepted as genuine, which they have flagged as not belonging to them, and which they are still checking. That record is useful both for your own ITC hygiene and, potentially, as evidence of due diligence if an ITC claim is ever questioned.

The three actions and what each one does

Accept moves the invoice toward inclusion in your GSTR-2B for the period, and from there into the ITC you can claim in GSTR-3B, assuming the other conditions for ITC eligibility under Section 16 are also met.

Reject excludes the invoice from your GSTR-2B calculation. This is the action for a document that does not belong to you: a supplier reported your GSTIN in error, an invoice was duplicated, or the transaction never actually happened on your side. Rejection is a statement about your own records, not a correction to the supplier's filing.

Pending holds the invoice without a decision. It does not enter GSTR-2B for the current period, and it remains available in IMS for you to act on in a later period. This is the action for something you need more time to verify, such as a delivery you have not yet received or an invoice whose amount does not match your purchase order.

No action is not a safe default

The most consequential detail in IMS is that silence resolves to acceptance. If you neither accept nor reject nor mark an invoice pending before GSTR-2B is generated for the period, the system treats it as accepted, and it enters your ITC calculation as though you had reviewed and approved it.

Where IMS sits in the monthly return cycle

IMS is populated continuously as suppliers file their GSTR-1 or use the Invoice Furnishing Facility, so invoices can appear in your dashboard throughout the month, not just at the end of it. GSTR-2B is generated on a fixed date each month based on supplier filings up to that point, and whatever state your IMS decisions are in at that moment is what flows into the GSTR-2B calculation. GSTR-3B, where you actually claim ITC, is filed after that, due on the 20th for monthly filers.

This means IMS review has its own effective deadline, tied to when GSTR-2B is generated, which is earlier in the cycle than the GSTR-3B due date most businesses are used to tracking. Treating IMS as a task for the last day before GSTR-3B is filed misses the point, since the GSTR-2B snapshot may already be locked in by then.

A monthly workflow for IMS review

1. Check the IMS dashboard at least weekly through the month, not only at month-end, since suppliers file on a rolling basis.
2. For each new invoice, match it against your purchase register or a corresponding purchase order and delivery record.
3. Accept invoices that match a confirmed, received supply with the correct amount and tax.
4. Reject invoices that do not belong to you: wrong GSTIN reported by the supplier, duplicates, or transactions that never occurred.
5. Mark genuinely uncertain invoices as pending, and set a reminder to revisit them before the next GSTR-2B generation date.
6. A few days before the GSTR-2B generation date, clear the backlog: nothing should be sitting unreviewed by default.
7. After GSTR-2B is generated, reconcile it against your purchase register one more time before filing GSTR-3B, since this is your last checkpoint before the ITC claim.

Reject vs ask for a credit note: two different fixes

A recurring mistake is treating IMS rejection as the fix for a supplier's mistake. It is not. If a supplier billed the wrong amount, applied the wrong rate, or invoiced the wrong entity but the underlying transaction is real, rejecting it in IMS only removes it from your GSTR-2B; the supplier's GSTR-1 still shows the original, wrong invoice, and their liability is unaffected. The actual fix is asking the supplier to issue a credit note and a corrected invoice, following the process in the credit note and debit note guide.

Reserve rejection for documents that are simply not yours: a GSTIN typo by a supplier that happened to match your number, an invoice for a transaction you have no record of, or a clear duplicate of one already accepted. For anything where a real transaction happened but the details are wrong, mark it pending, contact the supplier, and only accept once a correct document exists.

Common mistakes in IMS review

Accepting everything by default because deadlines are tight is the most common failure mode, and it defeats the purpose of having a review step at all. Rejecting a genuine invoice because the amount looks unfamiliar, without checking the purchase order first, is the opposite mistake, and it can delay legitimate ITC while the confusion gets sorted out. Leaving items pending indefinitely without a follow-up owner is a third failure mode: pending is a holding state, not a resolution, and ITC on a permanently pending invoice never reaches your credit ledger.

A fourth, quieter mistake is not checking IMS at all and assuming GSTR-2B will simply reflect what the business actually purchased. GSTR-2B increasingly reflects what suppliers report and what you did, or did not, do in IMS, which is precisely why the ITC mistakes and notice guide treats an unreviewed IMS dashboard as a risk factor in its own right.

Building IMS into the monthly close, not the filing scramble

The businesses that manage IMS smoothly treat it as a standing task through the month, owned by whoever handles purchase reconciliation, rather than a step squeezed in right before GSTR-3B is due. Software that shows purchase invoices and their IMS status side by side, alongside the sales-side data used to prepare your own GSTR-1 and GSTR-3B, makes the weekly check fast rather than a separate portal visit to remember.

myBillPlease brings together the invoice records, GSTR-1 preparation and GSTR-3B summary a business needs each month, and pairing that with a disciplined weekly IMS check on the GST portal closes the loop between what you sell, what you buy, and what actually reaches your ITC.

IMS turns ITC review into a weekly habit instead of a month-end guess. Accept what you can verify, reject what is not yours, hold what you are still checking, and never let the dashboard sit unreviewed until GSTR-2B has already locked in a decision you did not actually make.