GST Late Fee Calculator · 2026
GST late fee & interest calculator.
Enter the return type, days delayed and tax liability. The calculator works out the late fee and Section 50 interest — as per current rules, always verify the statutory cap on the GST portal before filing.
- Updated July 2026
- Built by CA Anil Agarwal
Interest under Section 50 applies only to GSTR-3B (tax paid in cash). GSTR-1 attracts late fee only, no interest.
Normal late fee: ₹50/day (₹25 CGST + ₹25 SGST).
Number of days from the due date to the actual filing date.
Net tax paid in cash (after ITC set-off) for the delayed period — interest applies on this amount.
Result
₹934.93
GSTR-3B — Normal return — 15 days delayed
- Late fee rate
- ₹50/day (₹25 CGST + ₹25 SGST)
- Late fee (uncapped)
- ₹750.00
- Interest @ 18% p.a.
- ₹184.93
- Total payable
- ₹934.93
Never calculate a late fee again.
TatvaBooks tracks your GST due dates and flags a return before it goes overdue. When it does slip, your books already have the numbers reconciled — filing is a review, not a scramble.
How it works
Late fee and interest are two separate charges.
Late fee — per day, per return
Late fee is charged for every day the return remains unfiled past its due date, regardless of whether tax is payable. For a normal return, the rate is ₹50 per day (₹25 CGST + ₹25 SGST). For a nil return — no outward supplies, no tax payable — the rate drops to ₹20 per day (₹10 CGST + ₹10 SGST). As per current rules, this is subject to a maximum cap that depends on your annual aggregate turnover in the preceding financial year, and the cap has been revised by notification in the past. This calculator shows the uncapped figure and flags that a cap may bring the number down — verify the applicable cap on the GST portal before you rely on the figure.
Interest — only on tax paid in cash
Interest under Section 50 of the CGST Act is charged at 18% per annum on the portion of tax liability that is discharged in cash (after adjusting available input tax credit), computed daily as tax × 18% × days delayed ÷ 365. Interest does not apply to a nil return, since there is no tax liability to delay. It also does not apply to GSTR-1, which is a statement of outward supplies rather than a tax payment — interest is a GSTR-3B concept.
Why the cap matters
Because the per-day rate has no built-in ceiling, a long delay can produce an uncapped figure well above what is actually payable. The Government has, through past notifications, capped total late fee based on turnover slabs (nil filers, up to ₹1.5 crore, ₹1.5–5 crore, and above ₹5 crore), with GSTR-1 and GSTR-3B sometimes carrying different caps. These slabs can change, so this calculator deliberately does not hard-code them — it shows the uncapped number as a starting point and directs you to the GST portal for the applicable cap before you finalize the amount to pay.
Beyond this calculator
This tool estimates late fee and interest for a single return. It does not account for late fee already paid, partial payments, or interest on delayed ITC reversal. For a full compliance calendar and automatic due-date tracking, see our GST guide.
Frequently asked questions
GST late fee calculator — common questions.
How is GST late fee calculated?
What is the maximum late fee cap?
How is GST interest calculated for late payment?
Does a nil GST return attract interest?
Is GST late fee different for GSTR-1 and GSTR-3B?
More tools
Stop tracking due dates in a notebook
Books that flag a return before it's overdue.
TatvaBooks watches your filing calendar, reconciles GSTR-2B automatically, and keeps your tax liability current — so late fee and interest become the exception, not the norm.