Missed the GSTR-3B or GSTR-1 due date? Late fee, interest and next steps

Short answer

File as soon as possible. Every day adds a late fee, and unpaid tax keeps adding 18% interest. File GSTR-1 first, then GSTR-3B.

Late fee

The late fee is charged in the next GSTR-3B and must be paid in cash. It can't be paid from ITC.

Interest

• 18% a year on the tax paid late, counted from the day after the due date to the day of payment.
• Interest is on the net cash liability only, that is, tax paid in cash after using ITC.
• Example: cash tax of ₹1,00,000 paid 20 days late → ₹1,00,000 × 18% × 20 ÷ 365 = ₹986.

What else goes wrong

• GSTR-1 blocked: you can't file the next GSTR-1 until the previous GSTR-3B is filed.
• Buyers lose ITC: your invoices don't reach their GSTR-2B until you file GSTR-1.
• E-way bills blocked after two months of non-filing (two quarters for QRMP filers).
• Notices and cancellation: continued non-filing leads to GSTR-3A and then cancellation.
• Three-year limit: a return can't be filed after three years from its due date.
• ITC deadline: ITC for a financial year must be claimed by 30 November of the next year, even in a late return.

What to do now

1. File pending GSTR-1s in order, oldest first.
2. Work out tax and ITC for each pending GSTR-3B; reconcile with GSTR-2B.
3. Deposit cash in the electronic cash ledger for tax, interest and late fee.
4. File the GSTR-3Bs in order.
5. If a GSTR-3A or REG-17 notice has arrived, reply after filing.

Related

• GSTR-3B: monthly summary return
• GSTR-1: statement of outward supplies
• GST registration cancelled or suspended?
• Compliance calendar: October to December 2026

Sources

• Rationalised late fee caps for GSTR-3B