GSTR-3B Summary Helper
GSTR-3B is the monthly self-assessed return through which tax is actually paid. The tricky part is Table 6.1: how much of each tax head can be paid from input tax credit and how much must come from the electronic cash ledger. The law prescribes a strict order of utilisation, and using it wrongly either blocks credit unnecessarily or results in a short payment with interest. Enter your outward liability, reverse-charge inward supplies, ITC available and reversals, and this helper applies the rules and shows the cash payable per head.
Set-off order (Section 49A, 49B and Rule 88A)
- IGST credit must be exhausted first — against IGST liability, then against CGST and SGST in any proportion you choose.
- CGST credit is used for CGST liability, then IGST.
- SGST/UTGST credit is used for SGST liability, then IGST.
- CGST credit can never pay SGST and vice versa.
- Reverse-charge liability (Table 3.1(d)) must be paid in cash; its credit becomes available in the same month under Table 4(A)(3).
The helper splits surplus IGST credit between CGST and SGST so that the cash outgo is minimised and balanced — the allocation most practitioners prefer and one the portal accepts.
Worked example
Outward tax: IGST ₹72,000, CGST ₹72,000, SGST ₹72,000. RCM payable CGST ₹2,500 + SGST ₹2,500. ITC: IGST ₹40,000, CGST ₹55,000, SGST ₹55,000, with reversals of ₹1,000 each under CGST and SGST. After taking RCM credit, net ITC is IGST 40,000, CGST 56,500, SGST 56,500. IGST credit of 40,000 fully pays part of IGST liability, leaving 32,000 IGST to be paid by CGST/SGST credits after they cover their own heads — which they cannot, because 56,500 < 72,000. Result: cash IGST ₹32,000, CGST ₹18,000 (15,500 + 2,500 RCM), SGST ₹18,000. Total cash ₹68,000 and nothing carried forward.
Why it matters
Interest at 18% per annum applies only on the portion paid in cash after the due date, so knowing the exact cash figure also tells you your interest exposure. Use the helper before creating the challan to avoid depositing excess under the wrong head, which can take months to re-allocate via PMT-09.
Frequently Asked Questions
Can I use CGST credit to pay SGST?
No. Cross-utilisation between CGST and SGST is prohibited. Only IGST credit can be used against both.
Must IGST credit be fully used before CGST/SGST credit?
Yes, since 1 April 2019 IGST credit must be exhausted first, though you may choose how to split the surplus between CGST and SGST (Rule 88A).
Can RCM tax be paid using ITC?
No. Reverse-charge liability must be paid through the cash ledger. The credit of that payment can be claimed in the same return.
What is the GSTR-3B due date?
The 20th of the following month for monthly filers; the 22nd or 24th of the month after the quarter for QRMP taxpayers depending on the state.
Disclaimer: This tool is for general information and estimation only. Tax rates and rules change — verify with official sources or a professional before acting. Read full disclaimer.