Stay compliant with our comprehensive GST filing checklist — GSTR-1, GSTR-3B, GSTR-9, and important deadlines.
GST compliance is less about complexity and more about rhythm. Most penalties businesses incur are not for getting the tax wrong — they are for filing late. Here is the full calendar for FY 2025-26 and the reconciliation habits that keep input tax credit from leaking.
Monthly and quarterly returns
- GSTR-1 — outward supplies. Due the 11th of the following month for monthly filers; the 13th of the month after quarter end for QRMP filers
- GSTR-3B — summary return and tax payment. Due the 20th of the following month; QRMP filers pay monthly via PMT-06 and file quarterly
- GSTR-2B — auto-generated static ITC statement, available on the 14th. This is your reconciliation source of truth
- CMP-08 — for composition dealers, due the 18th after each quarter
Annual returns
- GSTR-9 — annual return, due 31 December following the financial year. Mandatory above ₹2 crore turnover
- GSTR-9C — self-certified reconciliation statement, due with GSTR-9. Mandatory above ₹5 crore turnover
- GSTR-4 — annual return for composition dealers, due 30 April
The ITC rule that catches people out
Input tax credit can only be claimed on invoices that actually appear in your GSTR-2B. If your supplier has not filed their GSTR-1, the credit does not appear and you cannot claim it — regardless of whether you hold a valid tax invoice and have paid them. Reconcile purchase register against GSTR-2B every single month, and chase non-filing suppliers immediately rather than at year end.
The other hard deadline: credit for any invoice from a financial year must be claimed by 30 November of the following year, or the date of filing the annual return, whichever is earlier. After that the credit lapses permanently.
Late fees and interest
- GSTR-3B late fee — ₹50 per day (₹20 for nil returns), capped by turnover slab
- GSTR-1 late fee — ₹50 per day, ₹20 for nil returns
- Interest on delayed tax payment — 18% per annum on the net cash liability
- Interest on excess or wrongly availed ITC — 24% per annum
A practical monthly routine
- By the 5th — close the books for the previous month and lock the sales register
- By the 10th — reconcile sales register to e-invoice and e-way bill data, then file GSTR-1
- On the 14th — download GSTR-2B and reconcile against the purchase register
- By the 18th — resolve mismatches, chase suppliers on missing invoices
- By the 20th — finalise liability, pay tax, and file GSTR-3B