Small taxpayers opting for the QRMP scheme file Form GSTR-3B once every quarter, but tax payment remains monthly. For month 1 and month 2 of the quarter, liability is paid into the electronic cash ledger through a generated challan rather than a return.
Due date and legal rules for Form GST PMT-06
Under CGST Rules Rule 61(1) and Rule 61(3), a quarterly return filer deposits the tax due for each of the first two months by the 25th day of the month succeeding that month. The official GST portal guidelines confirm that QRMP taxpayers pay tax in the first two months using Form GST PMT-06 by the 25th of the succeeding month.
At the end of the quarter, the complete tax liability is discharged when filing quarterly Form GSTR-3B. To understand how GSTR-3B consumes cash and ITC, see our detailed guide on GSTR-3B meaning, format and how GSTR-2B feeds it.
Common mistake: Treating Form GST PMT-06 as a return filing. PMT-06 is only a payment challan that deposits cash into your electronic cash ledger. The tax is not adjusted against outward supplies until quarterly GSTR-3B is filed and debited under Rule 61(2).
Fixed sum method vs self-assessment method
When generating Form GST PMT-06 on the GST portal, taxpayers choose between two methods to determine their monthly cash deposit:
1. Fixed sum method (35 percent challan)
The portal auto-generates a pre-filled challan in Form GST PMT-06 for 35 percent of the net tax paid in cash in the previous quarter return (if quarterly GSTR-3B was filed). If the taxpayer was a monthly filer in the preceding tax period, the challan generates for 100 percent of the net cash paid in the last monthly return. No manual calculation of inward credit or outward sales is required.
2. Self-assessment method
The taxpayer assesses actual outward liability for the month, calculates eligible input tax credit from the auto-drafted GSTR-2B, and pays the net cash difference via Form GST PMT-06. This method suits businesses where turnover fluctuates sharply or where significant ITC covers the outward liability.
No payment required: If the balance in your electronic cash ledger or electronic credit ledger is sufficient to cover the cumulative tax liability for the month, or if the net cash liability is nil, you do not need to generate Form GST PMT-06 for that month.
Interest rules under Section 50 for QRMP monthly payments
Interest on late payment or shortfall is governed by CGST Act Section 50(1), which mandates interest at a rate not exceeding 18 percent per annum on unpaid tax:
- Under fixed sum method: If you deposit the full 35 percent challan amount by the 25th of the next month, no interest is payable for that month, even if the actual liability turns out higher when quarterly GSTR-3B is filed. If you pay after the 25th, interest runs from the 26th until the date of payment.
- Under self-assessment method: If the actual tax paid by the 25th falls short of the net tax finally determined in quarterly GSTR-3B, interest at 18 percent per annum applies to the shortfall from the 26th of the respective month until the date of payment.
Worked example: calculating monthly PMT-06 deposit and interest
Consider a taxpayer registered under QRMP for the quarter October to December. In the previous quarter (July to September), the net cash paid in GSTR-3B was ₹1,00,000 (CGST ₹50,000 and SGST ₹50,000).
| Calculation parameter | CGST (₹) | SGST (₹) | Total (₹) |
|---|---|---|---|
| Previous quarter net cash paid in GSTR-3B | 50,000 | 50,000 | 1,00,000 |
| Fixed sum requirement (35% of previous cash) | 17,500 | 17,500 | 35,000 |
| Deposit made in PMT-06 by 25 November | 17,500 | 17,500 | 35,000 |
| Actual October net tax liability (assessed later) | 25,000 | 25,000 | 50,000 |
| Shortfall for October (covered in final GSTR-3B) | 7,500 | 7,500 | 15,000 |
| Interest payable under fixed sum method | 0 | 0 | 0 |
Because the taxpayer deposited the full 35 percent fixed sum (₹35,000) on or before 25 November, zero interest is charged on the ₹15,000 difference for October. The remaining balance is discharged when quarterly GSTR-3B is filed in January.
Suppose instead the taxpayer opted for self-assessment, estimated ₹10,000 cash liability, but actual liability was ₹25,000, and paid the balance on 24 January with GSTR-3B (60 days delay from 25 November). Under self-assessment, interest applies on the unpaid cash shortfall:
Formula: Shortfall × 18% × (60 / 365) = ₹15,000 × 0.18 × (60 / 365) = ₹443.84, rounded to ₹444 under Section 170.
Step-by-step portal workflow to generate Form GST PMT-06
- Log in to the GST Portal and navigate to Services > Payments > Create Challan.
- Select the reason for challan as Monthly payment for quarterly return.
- Select the Financial Year and the Period (Month 1 or Month 2 of the active quarter).
- Choose your payment method: 35% Challan (auto-calculated) or Challan on self-assessment basis.
- Click PROCEED to generate the challan and complete payment via Net Banking, NEFT, RTGS, or Over the Counter.
Frequently asked questions
What is the due date for monthly payment in PMT-06 under QRMP?
For the first two months of a quarter, taxpayers under the QRMP scheme must deposit tax using Form GST PMT-06 by the 25th day of the succeeding month.
Is PMT-06 a return or a payment challan?
Form GST PMT-06 is a payment challan used to deposit money into the electronic cash ledger. It is not a tax return and does not adjust liability until quarterly GSTR-3B is filed.
What happens if there is a shortfall under the fixed sum method?
If you deposit 35 percent of the previous quarter cash liability by the 25th, no interest is charged for that month even if actual quarterly liability turns out higher, provided the final quarterly balance is cleared in GSTR-3B.
Check your own GSTR-2B
When using self-assessment under QRMP, accurate input tax credit matching prevents unexpected cash shortfalls. Your GSTR-2B and purchase register files are read in your browser and never uploaded to any server.
Last checked: 24 October 2026. Sources: CBIC CGST Rule 61, GSTN QRMP User Guide.