Between the 14th and the 20th of every month, finance teams have about six days to reconcile GSTR-2B against purchase registers, chase defaulting vendors, and file GSTR-3B. Miss a step and you either pay extra tax out of working capital or trigger a Rule 88D intimation.
New to the return? Our guide on what is GSTR-2B explains the basics first.
The key dates are fixed. Suppliers file GSTR-1 by the 11th. Quarterly filers use the Invoice Furnishing Facility (IFF) by the 13th. GSTN generates your monthly GSTR-2B statement on the 14th. GSTR-3B is due by the 20th.
Between the afternoon of the 14th and midnight of the 20th, finance teams have about six days, only five of them working days, to match thousands of purchase bills, chase defaulting vendors, resolve invoice number formatting discrepancies, claim IMS-pending credits, and compute final tax payments.
A single missed step or delayed reconciliation directly leads to two costly outcomes: paying extra cash liability out of working capital, or claiming ineligible ITC and getting an intimation under Rule 88D (Form DRC-01C), which asks you to pay the excess with interest or explain it.
The 6-Day Action Timeline
What to do once GSTR-2B is generated
Once GSTR-2B appears on the 14th, match it against your purchase register before preparing GSTR-3B. Spotting missing invoices, rate errors, and unfiled vendor returns early protects your input tax credit and prevents DRC-01C mismatch notices.
Day 1 (14th): Download GSTR-2B & Run First-Pass Matching
GSTR-2B for the previous month is generated on the 14th. Log into gst.gov.in, navigate to the Returns Dashboard, and download the GSTR-2B Excel spreadsheet.
Export your purchase register from your accounting software (Zoho Books, Busy, Tally, or custom ERP) for the return period. If you use Zoho, follow our Zoho Books reconciliation guide.
Drop both spreadsheets into gstr2bmatch.in to run instant client-side matching. The tool sorts your purchases into 5 buckets:
- Bucket A: Matched (lock these in).
- Bucket B: Tax or value mismatch (check rounding or freight inclusion).
- Bucket C: Missing in 2B (supplier has not filed GSTR-1).
- Bucket D: In 2B but missing from books (unrecorded vendor bills).
- Bucket E: Probable IMS Pending (active supplier, but specific bill missing).
Day 2 (15th): Launch Vendor Chasing & Audit IMS Pending
Filter invoices where suppliers have not filed GSTR-1 and send automated reminders via WhatsApp and Email. See the templates below.
Next, log into the GST portal and open the Invoice Management System (IMS) Dashboard. Review your Inward Supplies and look for invoices marked as Pending from your internal procurement audits. If goods have arrived and physical copies are verified, change the status from Pending to Accept. Invoices left in Pending do not appear in GSTR-2B or GSTR-3B Table 4A, so read our complete guide on how IMS Pending impacts ITC.
Day 3 (16th): Handle Credit Notes & Tax Mismatches (Bucket B)
Check for rounding discrepancies first. A difference of plus or minus ₹1 to ₹5 often comes from line-item versus total-level tax calculation. Confirm whether Reverse Charge Mechanism (RCM) or non-creditable items were incorrectly entered in the purchase register.
Then check Credit and Debit Notes (CDNR). Verify whether suppliers have issued Credit Notes against older invoices. Since the October 2025 tax period, IMS lets you keep a credit note Pending, but only for one tax period; after that a record with no action is deemed accepted (GSTN FAQ on IMS changes). Decide on a disputed credit note now rather than letting the clock run out.
Day 4 (17th): Late Supplier Uploads and Your IMS Cut-Off
If a supplier missed an invoice in the GSTR-1 filed on the 11th, they can add it through GSTR-1A before filing their own GSTR-3B. Be clear about what that buys you. A record filed after the 2B cut-off reaches your next month's GSTR-2B, not this one: the GSTN FAQ on IMS gives the example of a September credit note added through GSTR-1A on 14 October, which falls in the October GSTR-2B. So a late upload moves the credit by a month; it does not rescue this month's claim. Put those invoices on a carry-forward list and make sure all your IMS actions are saved by the evening of the 17th.
Day 5 (18th): Recompute GSTR-2B & Final Matching Pass
If you took action on any invoice in IMS (flipping from Pending or Rejected to Accept), your downloaded 2B does not update automatically. Go to your IMS Dashboard on gst.gov.in and click "Recompute GSTR-2B". Give the portal time to generate the revised statement, and do not leave this step for the 20th.
Download the recomputed GSTR-2B Excel and drop the updated file along with your final purchase register back into gstr2bmatch.in for a second pass.
Your Bucket A (Matched) total is now locked and represents your legally claimable Input Tax Credit under Section 16(2)(aa).
Day 6 (19th to 20th): Approve Table 4A, Pay Net Tax & File GSTR-3B
Open GSTR-3B and compare the auto-populated values in Table 4(A)(5) ("All other ITC") with your reconciled Bucket A total. Provide your finance or accounts payable desk with the final Bucket C export and ask them to withhold GST payment amounts from defaulting suppliers until next month's 2B reflection.
Generate the tax payment challan, clear net cash liability via NEFT, RTGS, or NetBanking, and file GSTR-3B a day early if you can, because the portal is busiest on the due date.
Vendor Follow-up Templates
When chasing defaulting vendors on the 15th, avoid generic reminders. Provide exact invoice details so their accounts team can act immediately.
Template 1: WhatsApp Reminder for Unfiled Invoices (Bucket C)
Template 2: Email Template for Disputed / IMS Missing Invoices
3 Fatal Mistakes to Avoid During the 6-Day Crunch
- Relying on GSTR-2A instead of GSTR-2B: GSTR-2A is a dynamic, continuously updating statement. GSTR-2B is the cut-off statement generated on the 14th, and your claim is limited to it under Rule 36(4). An invoice that shows up in 2A on the 16th belongs to next month's GSTR-2B; claim it then.
- Forgetting to click "Recompute GSTR-2B" after IMS actions: Accepting an invoice on your IMS dashboard does not update your GSTR-2B Excel or Table 4A automatically. You must manually trigger recomputation.
- Using slow, complex Excel macros on the 19th: Desktop spreadsheets loaded with nested VLOOKUP or XLOOKUP formulas freeze when processing thousands of records and frequently fail on invoice prefix variations such as forward slash versus hyphen versus leading zeroes.
Accelerate Your 6-Day Reconciliation with gstr2bmatch.in
Spending 10 hours of your 6-day crunch wrestling with Excel templates or uploading sensitive purchase registers to unknown cloud servers wastes time that could be spent on higher-value work.
gstr2bmatch.in handles the matching. Your files stay on your own computer. Nothing leaves the browser. The tool matches your files in the browser, no upload needed. Invoice number formats vary across vendors. The tool normalises them before matching so INV/2026/0891 and INV-2026-0891 are treated as the same invoice. After matching, the tool exports your results as CSV files. Use one for WhatsApp follow-ups and another for your IMS review.
Clear Your GSTR-2B Backlog in Minutes
File GSTR-3B on time and avoid cash flow loss from missed credits.
Reconcile my GSTR-2B →Last checked: 21 October 2026. Sources: GSTN IMS FAQ, GSTN FAQ on IMS changes from October 2025, GSTN GSTR-1A FAQ, GSTN GSTR-3B user guide.
Related guides
- what is GSTR-2B: the meaning of the return, what is in it and how it decides your ITC
- GSTR-2B generation date: when GSTR-2B is generated and which dates come before and after it
- GSTR-2B freeze date: what the monthly freeze date means