Verified · 29 Sept 2026
GSTR-1 vs GSTR-3B Reconciliation – Mismatch Checker
Compare month-wise tax in GSTR-1 and GSTR-3B. Spot short payments early, before an automated DRC-01B intimation blocks your next GSTR-1.
✓ Verified against official notifications · 29 Sept 2026 · How we verify →
Recent change: GSTR-3B for March 2026 extended to 21 April 2026 (21 Apr 2026)
| Month | Tax in GSTR-1 | Tax in GSTR-3B | Difference | Status |
|---|---|---|---|---|
| Apr | ₹0 | Matched | ||
| May | ₹0 | Matched | ||
| Jun | ₹0 | Matched | ||
| Jul | ₹1,00,000 | Short-paid | ||
| Aug | ₹0 | Matched | ||
| Sep | ₹0 | Matched |
Net difference (1 − 3B)
₹1,00,000
Months at DRC-01B risk
0
Difference > ₹25 lakh and > 20%
- Short payment in GSTR-3B: pay the difference with interest through DRC-03, or in the next GSTR-3B.
- Excess in GSTR-3B may mean invoices are missing from GSTR-1 — your buyers won't see that ITC in their GSTR-2B. Use GSTR-1A to amend.
FY 2026-27 · GST 2.0 slabs (5% / 18% / 40%) from 22 Sept 2025 · interest on net cash only (s.50 proviso, CBIC Circular 26/2022)Verify on gst.gov.in →Share on WhatsApp
For estimation only. This calculator applies the rules as we understand them on 29 Sept 2026. It is not legal or tax advice. Verify with the official notification or consult a Chartered Accountant / labour-law professional before filing or changing payroll.
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How DRC-01B is triggered
Rule 88C compares the tax you declared in GSTR-1 with the tax you paid in GSTR-3B for the same period. The portal issues DRC-01B when the shortfall is more than ₹25 lakh and more than 20% of the GSTR-1 figure. Both conditions must be met.
| GSTR-1 tax | GSTR-3B tax | Shortfall | DRC-01B? |
|---|---|---|---|
| ₹1.2 crore | ₹90 lakh | ₹30 lakh (25%) | Yes |
| ₹2 crore | ₹1.7 crore | ₹30 lakh (15%) | No: under 20% |
The second row is still a problem, just not an automated one. A gap that size comes up in scrutiny under ASMT-10, so it should be explained in your working papers even if no intimation arrives.
Legitimate reasons for a gap
- An invoice reported in GSTR-1 for one month but paid in an earlier GSTR-3B, or the other way round.
- Tax paid on an advance in GSTR-3B, with the invoice reported in GSTR-1 later.
- A credit note shown in one return and not yet in the other.
- An invoice wrongly marked as reverse charge in GSTR-1, where the buyer pays the tax.
- A GSTR-1 typo, corrected through GSTR-1A before GSTR-3B is filed.
Replying to DRC-01B
You have seven days, and GSTR-1 for the next period stays blocked until you respond. In Part B, either pay the difference through DRC-03 and quote the ARN, or explain it period by period. A reply that says “timing difference” without naming the invoices and the months they moved between is usually rejected. The notice reply generator has a free DRC-01B template.
When GSTR-3B is higher
Paying more in GSTR-3B than you declared in GSTR-1 does not trigger DRC-01B, but it usually means invoices are missing from GSTR-1. Your customers then cannot see that credit in their GSTR-2B. Add the invoices through GSTR-1A or the next GSTR-1.
Official sources
Frequently asked questions
When is DRC-01B issued?
When tax declared in GSTR-1 exceeds tax paid in GSTR-3B by more than ₹25 lakh and by more than 20%, for a tax period.
What happens if I ignore DRC-01B?
You can't file GSTR-1 for the next period until you pay the difference or explain it in Part B.
Why would GSTR-3B be higher than GSTR-1?
Usually invoices missing from GSTR-1. Your customers then can't see that ITC — amend through GSTR-1A or the next GSTR-1.