Every month between the 14th and the 20th, accountants and business owners face the same high-pressure task: matching their purchase register (books of accounts) with the data the government has on record. If you skip this process or get it wrong, you risk losing legitimate Input Tax Credit or facing notices for over-claiming.
This page is one part of our GSTR-2B reconciliation guide, which shows how the whole process fits together.
The core rule of GSTR-2B matching
The entire reconciliation process is driven by a single strict law: you cannot claim ITC just because you hold a valid tax invoice. According to Section 16(2)(aa) of the CGST Act, the details of the invoice must be furnished by the supplier in their GSTR-1 and communicated to you in your GSTR-2B.
Since 1 January 2022, Rule 36(4) of the CGST Rules enforces this by stating that no input tax credit shall be availed unless the details have been communicated to the registered person in FORM GSTR-2B. The old 5% provisional ITC buffer no longer exists.
Notice risk: If you claim ITC in GSTR-3B that exceeds the ITC available in your GSTR-2B beyond the notified threshold, you will receive an intimation in Form DRC-01C under Rule 88D. You are then required to pay the excess amount with interest or explain the difference.
The step-by-step reconciliation process
Reconciling your data requires bringing two data sources together and comparing them line by line.
- Download your GSTR-2B: For monthly filers, the GSTR-2B is generated on the 14th of the following month. You can download GSTR-2B from the GST portal in Excel or JSON format.
- Export your Purchase Register: Extract your inward supplies from your accounting software (like Tally, Zoho Books, or Marg) for the same tax period into an Excel file.
- Run the match: Compare the two files by aligning the Supplier GSTIN, Invoice Number, Invoice Date, and Tax Amounts (IGST, CGST, SGST).
How to handle reconciliation outcomes
Let us look at a realistic scenario for a business reviewing its ITC for a given month. Suppose your total purchase register shows ₹1,25,000 in potential ITC, but you need to verify which invoices are actually eligible.
| Invoice | In books | In GSTR-2B | Result |
|---|---|---|---|
| INV-2026/089 | ₹45,000 | ₹45,000 | Matched |
| BILL-142 | ₹18,000 | Nil | ITC blocked |
| INV-2026/092 | ₹12,000 | ₹12,000 | Check Section 16(2)(b) |
| TAX-405 | ₹50,000 | ₹50,005 | Rounding difference |
Here is what each outcome means for your GSTR-3B filing:
- Matched: The supplier filed correctly. You can safely claim this ITC in Table 4(A)(5) of your GSTR-3B, provided you have received the goods or services.
- In books, missing in GSTR-2B (ITC blocked): You cannot claim this ITC this month. You must contact the supplier and ask them to file their GSTR-1 or correct the GSTIN. A simple email is often the best first step.
- In GSTR-2B, missing in books: This often happens when a supplier bills you at the end of the month, but the goods are still in transit. Under Section 16(2)(b), you are not entitled to credit unless you have actually received the goods or services. You should defer this ITC to the next month.
- Value mismatch: Small differences often occur due to rounding. Section 170 of the CGST Act allows rounding off tax amounts to the nearest rupee. If the difference is substantial, investigate for typos or partial rejections.
The impact of the Invoice Management System (IMS)
The GST portal's Invoice Management System (IMS), live from 1 October 2024, adds a new layer to how reconciliation works. Instead of passively downloading GSTR-2B, you can now Accept, Reject, or keep Pending the inward invoices saved by your suppliers.
“Pending records will not become part of GSTR 2B and GSTR 3B. Such records will remain on IMS dashboard till the time same is accepted or rejected...” Source: GSTN FAQs on IMS
If you mark an invoice as "Pending" in IMS, it is explicitly excluded from that period's GSTR-2B. You can change the action from rejected to accepted later and recompute your GSTR-2B before filing GSTR-3B to claim the corresponding ITC.
Frequently asked questions
Can I claim ITC if the invoice is in my books but missing from GSTR-2B?
No. Under Section 16(2)(aa) and Rule 36(4), you cannot claim Input Tax Credit for invoices that have not been communicated to you in GSTR-2B.
When is GSTR-2B generated for reconciliation?
For monthly filers, GSTR-2B is auto-generated on the 14th of the following month based on the suppliers' GSTR-1 filings.
What happens if I claim more ITC in GSTR-3B than what is in GSTR-2B?
If the difference exceeds the notified threshold, you will receive an intimation in Form DRC-01C under Rule 88D, and you must either pay the excess ITC with interest or explain the difference.
Check your own GSTR-2B
Stop doing VLOOKUPs manually. Reconcile your GSTR-2B Excel or JSON file against your purchase register directly in your browser. Your GSTR-2B and purchase register files are read in your browser and never uploaded to any server.
For more details on setting up your workflow, read our GSTR-2B reconciliation complete guide.
Related guides
- GSTR-2B reconciliation with purchase register: matching your register with GSTR-2B invoice by invoice
- GSTR-2B vs purchase register: why the totals differ and how to find the difference
Last checked: 30 September 2026. Sources: CGST Act Section 16, Notification 40/2021-CT, GSTN Advisory on DRC-01C, GSTN FAQs on IMS.