GST IMS Explained for SMEs: Accept, Reject, Pending

As of 3 October 2026. IMS has run since the October 2024 tax period; the pending option for credit notes applies from the October 2025 tax period, and GSTN released an Excel-based IMS offline tool through an advisory in April 2026.

Key fact	Detail
What IMS is	A GST portal facility to accept, reject or keep pending inward supplies reported by suppliers
Live since	October 2024 tax period
Default if no action	Deemed accepted when GSTR-2B is generated
Recent changes	Pending allowed for credit notes from October 2025 tax period; offline tool from April 2026
Who it applies to	GST-registered recipients who claim input tax credit
Official source	GST portal (gst.gov.in)

This guide is for owners, accountants and finance teams of small and medium businesses in India that claim input tax credit. After reading it you will know what each IMS action does to your ITC, how to handle credit notes, what the GSTR-3B lock means, and how to set up a monthly routine that takes an hour instead of a day.

What is GST IMS and why it matters

GST IMS is a screen on the GST portal where every invoice, debit note and credit note your suppliers report appears for your action. Your choices there decide which documents reach GSTR-2B, and therefore how much input tax credit you can claim.

Before IMS, your ITC was whatever suppliers uploaded, and disputes were handled later by reversal or notice. IMS moves the decision to the start of the cycle. You confirm what you actually received, reject what you did not, and park what is under discussion. It sounds like extra work, but it is the cheapest point to catch a wrong invoice.

Accept, reject or pending: what each IMS action does

Accept puts the document into GSTR-2B as available credit. Reject keeps it out. Pending keeps it out for now and carries it forward. No action is treated as accepted when GSTR-2B is generated, so silence is a decision.

Action	Effect on GSTR-2B	Effect on your ITC	Use it when
Accept	Included	Credit available in this period	Goods or services received and invoice correct
Reject	Excluded	No credit; supplier must correct or amend	Invoice not yours, wrong value, wrong GSTIN, duplicate
Pending	Excluded this period, carried forward	No credit until you accept later	Goods not yet received, quantity or price dispute
No action	Deemed accepted	Credit available	Only if you have checked and agree

Pending is not unlimited. The portal limits how long a document can stay pending, and some document types cannot be kept pending at all. Check the current rules on the GST portal before relying on pending for old invoices.

How IMS affects GSTR-2B and GSTR-3B

GSTR-2B is generated on the 14th of the following month from your IMS actions, and its ITC figures flow into GSTR-3B. If you change IMS actions after the 14th, you can recompute GSTR-2B, but only before you file GSTR-3B for that period.

The output side has also tightened. From the July 2025 tax period, the tax liability auto-populated in GSTR-3B from GSTR-1, GSTR-1A and IFF is non-editable. If your outward supply data is wrong, you fix it through GSTR-1A before filing GSTR-3B. Together, these changes mean GSTR-3B is increasingly a result of upstream data, not a form you adjust at the end.

1. Suppliers file GSTR-1 or IFF; documents appear in your IMS.
2. You accept, reject or keep pending, ideally before the 14th.
3. GSTR-2B generates on the 14th.
4. If needed, change actions and recompute GSTR-2B.
5. File GSTR-3B with ITC from GSTR-2B and liability from GSTR-1 or GSTR-1A.

How to handle credit notes in IMS

From the October 2025 tax period, you can keep a credit note pending for a limited time instead of accepting or rejecting it immediately. When you accept a credit note, you can declare the ITC reversal only to the extent you actually availed.

Credit notes reduce your ITC, so accepting one means reversing credit. Before this change, accepting a credit note for an invoice whose ITC you had partly claimed was awkward. Now you can keep it pending while you check, add remarks for the supplier, and when you accept, adjust the reversal amount to the credit you actually took. As reported, monthly filers get one extra tax period and quarterly filers one extra quarter before a pending credit note must be decided.

Practical rule: never accept a credit note until your accounts team has matched it to the original invoice and the quantity or rate difference it represents.

How to use the IMS offline tool for bulk actions

The IMS offline tool is an Excel-based utility from GSTN that lets you download IMS data, take accept, reject or pending actions in bulk offline, and upload the result. It suits businesses with hundreds of inward documents a month.

GSTN announced the tool in an advisory in April 2026. You download it from the Offline Tools section of the GST portal, enable macros, import your IMS data, mark actions and upload the file. For a trader with 40 purchase invoices a month, the online screen is fine. For a manufacturer receiving 600 invoices from raw material suppliers, transporters and job workers, the offline tool, or a direct reconciliation in your accounting software, saves hours.

A monthly IMS routine for SMEs

A good IMS routine reconciles supplier uploads against your purchase register by the 10th, takes actions by the 12th, checks GSTR-2B on the 14th, and files GSTR-3B after one final review. One person should own it.

• Day 1 to 10: record all purchase bills in your accounting software with supplier GSTIN, invoice number and tax amounts.
• Day 10: download IMS data and match by GSTIN, invoice number, date and value.
• Day 11 to 12: accept matched documents, reject wrong ones with remarks, keep disputed ones pending, and call suppliers whose invoices are missing.
• Day 14: review GSTR-2B against your expected ITC.
• Before GSTR-3B: final check, then file.

Common IMS mistakes that cost SMEs input tax credit

The costliest IMS mistakes are rejecting a correct invoice by accident, relying on deemed acceptance without review, and accepting credit notes before matching them. Each one either loses credit you are owed or claims credit you must later reverse with interest.

• Rejecting instead of keeping pending: a rejected invoice needs the supplier to act before you can claim it. If you only need time, use pending where it is allowed.
• Ignoring quarterly filers: suppliers who file quarterly may upload invoices late, so missing documents are not always errors.
• Wrong GSTIN on purchase bills: multi-state businesses sometimes receive invoices on the wrong registration. Reject them with a remark and ask for a corrected document.
• No remarks: a short reason on each rejection or pending entry speeds up the supplier's correction.

What we see in IMS reconciliation for Gujarat businesses

For accounting clients in Rajkot, Morbi and Surat, the most common IMS problems are not about the portal. They come from purchase bills entered late, invoice numbers typed differently from the supplier's version, and transporters or job workers who upload in bulk at quarter end.

• A ceramic tile manufacturer in Morbi had about 15% of invoices failing to match only because of invoice number formats, such as leading zeros and prefixes. A normalised match key fixed most of them.
• A textile trader in Surat had frequent rate-difference credit notes from mills. Keeping them pending until the debit note was agreed avoided reversing ITC twice.
• A casting unit in Rajkot relied on deemed acceptance for months, then found a supplier had uploaded the same invoice twice. Active review caught the next one before GSTR-2B.

How to decide if your accounting software is IMS-ready

Your accounting software is IMS-ready if it imports supplier data from the portal, matches it to your purchase register automatically, flags mismatches with reasons, and lets you record the IMS action against each bill so the audit trail stays in one place.

Capability	Why it matters
Portal data import (IMS or GSTR-2B)	No manual retyping
Fuzzy matching on invoice number and value	Handles format differences
Action status per purchase bill	Accept, reject, pending visible in your books
Credit note linking to original invoice	Correct ITC reversal amount
Supplier follow-up list	Missing or wrong invoices chased before the 14th

If your team reconciles in spreadsheets today, the time saved usually justifies the change within a year. Our GST billing software requirements and e-invoicing requirements posts cover the rest of the feature list.

Related reading and next step

See our accounting and GST billing software, the 57th GST Council meeting guide, GST billing software requirements and inventory management software that ties purchases to stock. For a fixed quote on IMS reconciliation inside your accounting system, contact us through the contact page or WhatsApp +91 7265004040.