GST Return Deadlines: A Practical Calendar for FY 2026-27

Every recurring GST due date this year, and a simple system for never missing one.

Why GST deadlines catch businesses off guard

Most missed GST deadlines aren't caused by not knowing the due date — they're caused by the return depending on information that wasn't ready in time: a vendor invoice that arrived late, a bank statement that hadn't been reconciled, or a sales register that was still being finalised. Fixing the deadline problem usually means fixing the information flow ahead of it, not just marking a calendar.

The recurring dates that matter most

For most regular filers, three dates repeat every month without fail: GSTR-1 for outward supplies, GSTR-3B for the summary return and tax payment, and the due date for any TDS deducted the previous month. On top of these, advance tax instalments fall quarterly, and annual returns and reconciliations come once a year.

The businesses that never miss a filing tend to work backward from the deadline with a fixed internal buffer — closing their books five to seven working days before the actual due date, so there's always room to catch an error before it becomes a compliance problem.

Building a system instead of relying on memory

• Reconcile bank transactions weekly, not monthly, so nothing piles up
• Set an internal deadline several days ahead of the statutory one
• Keep a running folder of vendor invoices as they arrive, not at month-end
• Review the filing summary with someone before it's submitted, every time

None of this requires new software or a bigger team — it requires a fixed rhythm. That's ultimately what a good compliance function is: a schedule that runs whether or not anyone remembers to think about it that week.