GST Filing in 2026: Updated Compliance Calendar & Penalties Explained

Key due dates, late-fee structure and the changes every registered business must track this year.

GST compliance runs on a strict monthly and annual rhythm. Missing a return does not just attract late fees — it can block your input tax credit and, in repeated cases, lead to suspension of your registration.

The core returns to track

• GSTR-1 — outward supplies, filed monthly or quarterly under QRMP.
• GSTR-3B — summary return and tax payment, the most critical monthly filing.
• GSTR-9 / 9C — annual return and reconciliation for eligible taxpayers.

Penalties for late filing

Late fees accrue per day of delay for each return, subject to a cap, plus interest on any unpaid tax. The bigger cost is usually commercial: buyers may withhold payment if your filings do not reflect in their credit ledger.

How to stay ahead

Reconcile your books with the GST portal every month, not just at year-end. A simple internal calendar with reminders three days before each due date eliminates the vast majority of late filings.

Written by

CA Meera Deshmukh

Tax Lead, Legal Door LLP