GSTR-2B and IMS Reconciliation: A Monthly Routine to Protect Your Input Tax Credit

Input tax credit is cash. When an invoice is missing from GSTR-2B, or sits wrongly in the Invoice Management System (IMS), that cash stays locked until the supplier corrects it. If no one notices, it may be lost. Here is a monthly routine any business can follow, and the parts of it that AI can now take over.

Why GSTR-2B and IMS matter more now

• IMS sits between your supplier and your credit. Invoices your suppliers report in GSTR-1, GSTR-1A or IFF appear on your IMS dashboard, where you can accept, reject or keep them pending.
• Inaction counts. An invoice you take no action on is generally treated as accepted when GSTR-2B is generated, including one you should have rejected.
• GSTR-2B decides what you can claim. The draft GSTR-2B for a month is generated around the 14th of the next month, and the portal increasingly restricts ITC in GSTR-3B that is not supported by GSTR-2B.
• There is a time limit. Credit that is not claimed within the period allowed under Section 16(4) of the CGST Act is lost for good.

The monthly routine

1. Close your purchase register first. Make sure every purchase bill for the month is entered in Tally, Zoho or your accounting software, with the correct GSTIN, invoice number, date and tax.
2. Download IMS and GSTR-2B data. Take the IMS records during the month, and the draft GSTR-2B once it is generated.
3. Match invoice by invoice. Match on supplier GSTIN, invoice number and amount. Sort the results into four lists: matched; in your books but not in 2B; in 2B but not in your books; and amount or rate mismatches.
4. Act in IMS before filing. Accept what is correct, reject what is wrong or not yours, and keep pending what you are still checking. Recompute GSTR-2B where required.
5. Follow up with suppliers. Write to each supplier whose invoice is missing or wrong, with the invoice details and the correction needed.
6. Track until resolved. Carry unresolved invoices forward each month and claim the credit when the supplier corrects their return, within the time limit.
7. Watch supplier behaviour. Suppliers who often file late or make mistakes are a risk to your working capital. Note them, and review payment terms where needed.

What AI can do in this routine

Steps 2 to 5 and step 7 are mostly repetitive and suit automation well:

• Matching thousands of lines from your books against IMS and 2B data in minutes, including near-matches such as invoice numbers with extra characters or different date formats.
• Producing the four exception lists, with the credit amount at stake for each supplier.
• Drafting a supplier follow-up email or WhatsApp message for each exception, ready for your approval.
• Keeping a running tracker of unresolved credit and suppliers with repeat mismatches.
• Running the check weekly in busy months, not only in the days before 3B is due.

The decisions stay with a person: what to accept or reject in IMS, whether a credit is eligible, and what goes into the return. That is where a Chartered Accountant’s review matters.

Common mistakes to avoid

• Waiting until the 18th or 19th to start reconciliation, which leaves no time for supplier corrections.
• Accepting every invoice in IMS without checking, or leaving the dashboard untouched.
• Claiming credit on invoices that are not in GSTR-2B and hoping to fix it later.
• Not keeping a record of supplier follow-ups, which helps if the credit is questioned in a notice or audit.

How SSRA & Co. can help

Our GST team handles returns and reconciliations for businesses across South Delhi. We can also set up an AI-assisted reconciliation that runs on your own accounts and brings you only the exceptions. See AI automation for businesses in South Delhi.

Frequently asked questions

What is the difference between GSTR-2A and GSTR-2B?
GSTR-2A changes as suppliers file and is useful for tracking. GSTR-2B is a monthly statement generated around the 14th, and is the one used for claiming ITC in GSTR-3B.

What happens if I do not take any action in IMS?
Invoices with no action are generally treated as accepted and flow into GSTR-2B. Check them, especially invoices that are not yours or have wrong amounts.

Can AI file my GST return?
AI can prepare and check the working papers. Filing, and the judgement on what credit to claim, should stay with you and your professional.

This article is general information as of November 2026 and not advice on any specific case. GST procedures change often; check the latest GSTN advisories before acting.