How to reconcile GSTR-2B with your accounting software

Every month, accountants and business owners face the same high-pressure routine between the 14th (when GSTR-2B is generated) and the 20th (when GSTR-3B is due for monthly filers). The task is straightforward in theory but complex in practice: ensure that the input tax credit (ITC) recorded in your accounting software perfectly matches what the government has recorded for you. If you get it wrong, you either leave your own money on the table or face immediate notices and penalties.

Working with Tally as well? Our guide to GSTR-2B reconciliation in Tally Prime shows the full flow.

This guide explains the exact steps to export your purchase register from common systems like Zoho Books, Busy ERP, or a generic spreadsheet, download your GSTR-2B, and run a proper reconciliation to find exactly where your ITC is blocked. We will also cover how recent changes, such as the Invoice Management System (IMS) and Form GSTR-1A, impact this vital monthly workflow.

The core rule: no GSTR-2B, no input tax credit

The legal framework for claiming input tax credit is absolute. You cannot claim ITC simply because you possess a physical tax invoice. According to Section 16(2)(aa) of the CGST Act (effective from 1 January 2022), ITC can be claimed only if the invoice details were furnished by the supplier in their statement of outward supplies (GSTR-1) and such details have been communicated to you in GSTR-2B.

Additionally, Section 16(2)(b) of the CGST Act dictates that a registered person is not entitled to credit of input tax unless they have actually received the goods or services. Even if the invoice is in your GSTR-2B, if the goods have not reached your premises, the ITC is not yet eligible.

There is no longer any provisional buffer. Before 1 January 2022, there was a provisional ITC buffer of initially 20%, then 10%, and finally 5% under an older version of Rule 36(4). Today, Rule 36(4) of the CGST Rules strictly states that no ITC shall be availed by a registered person unless the details of such invoices or debit notes have been communicated to them in Form GSTR-2B.

The stakes for non-compliance are severe. If there is a difference between the ITC available as per GSTR-2B and the ITC claimed in GSTR-3B that exceeds a pre-defined limit, you will receive an intimation in Form DRC-01C. You are then mandated to file Form DRC-01C Part B to provide the necessary details, reconcile the difference, or pay the excess amount. If you are found to have wrongly availed and utilised ITC, interest is charged at 18% per annum under Section 50(3) of the CGST Act.

Step 1: Export your purchase register

The reconciliation process begins with your own data. To match against the GST portal's records, you need a clean Excel file from your accounting software. importantly, this file must contain the supplier's GSTIN, the invoice number, the invoice date, the taxable value, and the tax amounts.

Exporting from Zoho Books

If you use Zoho Books, the default purchase export works perfectly for this process.

1. Navigate to reports: Open Zoho Books and go to the Reports module.
2. Select purchases: Under the Purchases section, click on Purchase Register or Bills.
3. Set the date range: Select the specific month you are reconciling (e.g., 1 to 30 September).
4. Export to Excel: Click the Export icon and choose Excel (.xlsx). The default export usually contains columns like Vendor Name, GSTIN/UIN, Bill#, Bill Date, Total, and Tax Amount.

Exporting from Busy ERP

Busy ERP is heavily used by Indian accountants and provides a reliable standard export.

1. Open the reports menu: Go to Display → Account Books → Purchase Register.
2. Select the format: Choose the standard format.
3. Filter the dates: Enter the start and end dates for the month.
4. Export: Click the Export button and select Excel. The known default columns include Party Name, GSTIN/UIN, Voucher No., Voucher Date, Gross Amount, and Tax Amount.

Exporting from other systems or manual Excel

If you use ERPNext, Tally Prime, Marg, or simply maintain your records in a manual spreadsheet, the logic remains identical. You must ensure your file has clear column headers. You must have the supplier's GSTIN, your document number, the document date, and the tax amounts. Save the file in .xlsx or .csv format.

Dealing with multiple GSTINs

If your business operates across multiple states, you will have a separate GSTIN for each state. The GST portal generates a separate GSTR-2B for each GSTIN. When exporting your purchase register from an ERP like Zoho Books or Tally, ensure you filter the export by the specific branch or state GSTIN. Reconciling a consolidated company-wide purchase register against a single state's GSTR-2B will result in massive mismatches, as invoices meant for other branches will show up as missing in your reconciliation report.

Step 2: Download your GSTR-2B from the GST portal

Your GSTR-2B for a month is generated on the 14th of the following month for monthly filers. It contains the invoices filed by your suppliers in their GSTR-1 by their respective due dates (the 11th day of the succeeding month for monthly filers, and the 13th day of the month succeeding the end of the quarter for quarterly filers). This document is static; once generated, it serves as the definitive source for your eligible ITC for that month.

1. Log in: Go to the GST portal and log in with your credentials.
2. Navigate to returns: Click on Services → Returns → Returns Dashboard.
3. Select period: Select the Financial Year and the Return Filing Period, then click Search.
4. Download GSTR-2B: Under the Auto-drafted ITC Statement GSTR-2B box, click the Download button.
5. Choose Excel: Click the button to download the Excel file. The downloaded Excel contains multiple sheets, including B2B, B2BA, CDNR, and CDNRA tables. You will primarily use the B2B sheet to reconcile regular purchase invoices, while the CDNR sheet contains credit and debit notes.

Step 3: Match invoices and identify the gaps

Once you have both Excel files, you must compare them line by line. The process involves matching the GSTIN and the invoice number, followed by a check on the tax values. This effectively splits your invoices into distinct buckets:

• Matched: The invoice is present in both your books and GSTR-2B, and the tax values match perfectly (or within a ₹1 rounding tolerance). This ITC is safe to claim in GSTR-3B.
• Value mismatch: The invoice exists in both, but the supplier has declared a different tax amount than what you recorded. You must investigate which figure is correct.
• Missing from GSTR-2B: You have the purchase invoice, but the supplier has not filed their GSTR-1, or filed it late. This ITC is blocked until they file.
• Not in books: An invoice appears in your GSTR-2B, but you have no record of it in your purchase register. It might be a missed entry, or a supplier billing you by mistake.
• IMS Pending: A special case where the invoice is missing from your GSTR-2B because action is required in the Invoice Management System on the GST portal.

Worked example: a standard monthly reconciliation

Consider a small manufacturing business reconciling their September 2026 purchases. They have downloaded their GSTR-2B on 14 October and exported their Zoho Books purchase register. They compare the two files to see exactly where they stand.

In this scenario, the business can confidently claim the ₹18,000 ITC for Steel Traders. They must investigate the ₹900 discrepancy for Fast Logistics. For Tech Supplies, the ₹12,000 and ₹6,000 ITC are blocked; they must check if the supplier failed to file, or if the invoices are caught in the IMS dashboard. Finally, they need to verify if the RT-99 invoice for ₹1,200 from Office World is a legitimate business expense that their accountant forgot to record in their software.

Common reasons for mismatches and how to fix them

The invoice is stuck in IMS Pending

The Invoice Management System (IMS) went live on the GST portal on 1 October 2024. It allows recipients to Accept, Reject, or keep Pending each inward invoice that a supplier files. importantly, invoices kept Pending in IMS are not included in that period's GSTR-2B or GSTR-3B. If you leave an invoice as Pending on your IMS dashboard, it will simply vanish from your GSTR-2B Excel download, and your ITC will be blocked.

To fix this, you must log into the GST portal, navigate to the IMS Dashboard, find the pending invoices, and change the action to Accepted. The portal allows a recipient to change the action from rejected or pending to accepted in IMS, recompute GSTR-2B at the time of filing GSTR-3B, and then take the corresponding ITC in that GSTR-3B.

Supplier has not filed GSTR-1

If an invoice is missing from GSTR-2B entirely and is not in IMS, the supplier likely failed to file their GSTR-1 by the due date. You must follow up with the supplier, as you cannot claim this ITC until they file.

If a supplier misses an invoice in their initial GSTR-1, they have a way to fix it quickly. Form GSTR-1A allows a supplier to amend any supply record or add a new supply record for the same tax period. This can be done after filing GSTR-1 and before filing GSTR-3B. If they file GSTR-1A in time, the invoice can still make it into your GSTR-2B before you file your returns.

Rule 37: 180 days non-payment

Sometimes you have the invoice, and it matches perfectly in GSTR-2B, but you have not paid the supplier. Under Rule 37 of the CGST Rules, if a registered person avails ITC but fails to pay the supplier the invoice value and tax within 180 days from the date of issue of the invoice, they must pay an amount equal to the ITC availed along with interest. You can re-avail the credit later when you finally make the payment. Always check your accounts payable aging reports during the reconciliation process to identify vendors unpaid beyond 180 days.

Formatting differences in invoice numbers

A frequent headache during reconciliation is formatting variations. A supplier might enter the invoice as INV/26-27/045 on the portal, while your accountant typed INV-2627-45 into Zoho Books. Standard Excel formulas like VLOOKUP will fail to match these, showing them as missing or mismatched. Under Rule 46(b) of the CGST Rules, an invoice number must be a consecutive serial number not exceeding sixteen characters, containing only alphabets, numerals, and special characters (hyphens and slashes). A good reconciliation process involves standardising these numbers by removing special characters, spaces, and leading zeros before comparing them.

Value mismatches and rounding differences

Section 170 of the CGST Act states that the amount of tax payable, interest, penalty, or refund due must be rounded off to the nearest rupee. Sometimes, an ERP calculates tax at the line-item level and rounds each line, while the supplier's system calculates it at the document total level, leading to a difference of a few paise or exactly a rupee. A mismatch of ₹1 is acceptable and can generally be ignored, but larger discrepancies require contacting the supplier to issue a debit or credit note to correct the value on the portal.

How to handle credit notes (CDNR) in reconciliation

Credit notes and debit notes present a unique challenge. When you download the GSTR-2B Excel from the GST portal, these documents appear on separate sheets named CDNR (Credit/Debit Notes Registered) and CDNRA (Amendments). If a supplier issues a credit note to reduce the value of a previous invoice, it reduces your eligible ITC for the month. You must match these credit notes against the credit notes recorded in your own ERP system. If you fail to account for a credit note that appears in GSTR-2B, you will overclaim ITC, which triggers a mismatch under Rule 88D and invites a DRC-01C notice.

Input service distributor (ISD) changes

For businesses with multiple branches, note that any office receiving tax invoices for input services on behalf of distinct persons must mandatorily register as an Input Service Distributor (ISD) and distribute the ITC. This rule, amended under Section 20 by the Finance Act 2024, becomes mandatory from 1 April 2025. If invoices are billed to the head office but belong to a branch, proper ISD distribution mechanisms must be followed rather than simply claiming it in the local GSTR-3B.

Filing GSTR-3B and GSTR-9

Once you complete the reconciliation, the eligible ITC auto-populates on a net basis from the system-generated Form GSTR-2B directly into Table 4(A)(5) of your GSTR-3B, labelled "All other ITC". You should verify that the figure auto-populated here matches the "Matched" total from your reconciliation exercise.

Later in the year, when you file your annual return (GSTR-9), this data flows again. From FY 2023-24 onwards, Table 8A of GSTR-9 will be auto-filled based on the details auto-populated in Form GSTR-2B, and this field is non-editable. Getting your GSTR-2B reconciliation right every single month ensures that your annual return process is smooth and free from massive, unexplainable discrepancies.

You must also keep track of the absolute time limit for claiming ITC. Under Section 16(4) of the CGST Act, a registered person shall not be entitled to take input tax credit in respect of any invoice or debit note after the 30th day of November following the end of the financial year to which the invoice pertains, or the date of furnishing the relevant annual return, whichever is earlier.

Frequently asked questions

Related guides

• GSTR-2B reconciliation in Tally Prime: the step-by-step guide
• Zoho Books GSTR-2B: reconciling Zoho Books bills without API access
• Busy ERP GSTR-2B reconciliation: the Busy ERP step-by-step guide

Last checked: 30 September 2026. Sources: CGST Act (CBIC), CGST Rules, GSTN IMS FAQs.