Updated 5 November 2026. A plain-language guide for business owners, not legal or tax advice. Check the latest GSTN advisories on the GST portal and speak to your CA.
Short answer: the Invoice Management System (IMS) is the inbox on the GST portal where every invoice, debit note and credit note your suppliers report against your GSTIN appears. You can accept, reject or keep it pending. Anything you do not act on is treated as accepted when GSTR-2B is generated. Accepted documents feed your GSTR-2B and the ITC in your GSTR-3B, so a few minutes in IMS each month decides how much credit you claim.
How IMS fits into your monthly GST cycle
IMS went live in October 2024, according to ClearTax, and is now part of every monthly return. The sequence is:
- Your supplier reports the invoice in GSTR-1, IFF or GSTR-1A.
- It appears in your IMS dashboard.
- You accept, reject or keep it pending (or do nothing).
- Draft GSTR-2B is generated on the 14th of the following month.
- Accepted items auto-populate ITC in your GSTR-3B.
What each action does
| Action | Effect on GSTR-2B | Effect on your GSTR-3B |
|---|---|---|
| Accept | Shown under ITC available | Credit auto-populates |
| Reject | Shown under ITC rejected | No credit; supplier's liability may rise in the next period |
| Pending | Left out for that month, carried forward | No credit yet; can be claimed later within the section 16(4) time limit |
| No action | Deemed accepted | Credit auto-populates |
These points come from GSTN's revised advisory on IMS.
The 14th and recomputing GSTR-2B
You can act in IMS until you file GSTR-3B for the period. If you accept, reject or change anything after the 14th, you must recompute GSTR-2B on the portal so that the change flows into GSTR-3B. GSTR-2B is also sequential: a month's GSTR-2B is generated only after the previous month's GSTR-3B is filed. QRMP taxpayers get GSTR-2B quarterly, with none for the first two months of the quarter.
Credit notes need extra attention
Credit notes reduce the credit you can claim, so the rules are stricter:
- Limited pending: GSTN's advisory listed credit notes and certain amendments as records that could not be kept pending. ClearTax reports that from the October 2025 tax period these "specified records" can be kept pending for one tax period only (one month for monthly filers, one quarter for QRMP), after which they are deemed accepted.
- Reversal amount: when you accept a credit note, the portal asks whether ITC needs to be reduced. You can now declare a full, partial or nil reversal, with a remark where it is partial or nil (ClearTax, citing GSTN's October 2025 update).
- Rejecting a credit note: if you reject it, the supplier's tax liability goes back up in their next GSTR-3B, so talk to the supplier before you reject.
When to accept, reject or keep pending
Accept
The goods or services were received, the invoice matches your purchase order and purchase entry, the GSTIN, rate and place of supply are correct, and the supplier has charged the right tax.
Reject
The invoice is not yours, it is a duplicate, the amount or rate is wrong and the supplier will issue a fresh document, or the transaction never happened. Add a remark so the supplier sees the reason.
Keep pending
The goods have not reached you yet, or you are waiting for the supplier to confirm a correction. Do not leave items pending for too long: credit for a financial year cannot be taken after 30 November of the next year. For FY 2025-26 that date is close, as explained in our post on the ITC last date for FY 2025-26.
A simple monthly IMS routine
| When | What to do |
|---|---|
| 1st to 11th | Post all purchase bills in your books. Chase suppliers whose invoices are missing from IMS. |
| 12th to 14th | Match IMS against your purchase register. Accept matched items, reject wrong ones, keep genuinely incomplete ones pending. |
| After the 14th | Review draft GSTR-2B. If you changed anything, recompute GSTR-2B. |
| Before GSTR-3B | Check credit notes and reversals, then file GSTR-3B by the due date. |
Bulk actions and an offline Excel tool (released in April 2026, per ClearTax) help when you have hundreds of invoices.
Who in your team should own IMS
In most small businesses the person who books purchase bills is best placed to act in IMS, because they already know which goods arrived and which bills are disputed. Your CA or accountant can then review rejections and credit note reversals before GSTR-3B is filed. Writing down simple rules, for example "reject only after emailing the supplier" and "never leave anything pending for more than one month without a note", keeps decisions consistent when staff change.
IMS and the year-end deadline
IMS also shapes your annual return. Table 8A of GSTR-9 is built from GSTR-2B, so what you accepted, rejected or kept pending during the year shows up there. Before you file GSTR-9 for FY 2025-26, review anything still pending for that year and decide on it before 30 November 2026. Our guide to GSTR-9 and GSTR-9C for FY 2025-26 covers the rest of the year-end checklist.
Common mistakes
- Ignoring IMS and relying on deemed acceptance, so wrong or fake invoices flow into GSTR-3B.
- Rejecting invoices without telling the supplier, which leads to disputes and duplicate documents.
- Taking action after the 14th and forgetting to recompute GSTR-2B.
- Leaving invoices pending past the section 16(4) time limit, so the credit is lost.
Automating IMS reconciliation
IMS works best when your purchase data is already clean. Good billing or ERP software can import IMS and GSTR-2B data, match it with purchase entries and suggest accept, reject or pending for each line, leaving your team to review exceptions only. Read our GST billing software checklist and Tally vs custom billing software. Nextinera builds ERP software and GST API integrations for Indian businesses. Book a free call to discuss your workflow.