GST Return Filing Deadlines 2026: Monthly Calendar

Gst Return

GST Return Filing Deadlines 2026: A Month-by-Month Compliance Calendar

Here’s something almost every GST-registered business has done at least once: opened the portal on the 19th of the month, realized GSTR-3B is due the next day, and scrambled through invoices at 11 PM. It’s a completely avoidable scramble — and yet it happens to first-time filers and seasoned business owners alike, mostly because nobody sat them down and explained the actual rhythm of GST compliance.

So let’s fix that. This is a plain, no-nonsense breakdown of which GST returns are due when in 2026, who they apply to, and what happens if you miss them.

First, Know Which Return Applies to You

Not every business files the same return on the same schedule. It depends on your registration type and turnover:

Regular taxpayers file GSTR-1 (outward supplies) and GSTR-3B (summary return + tax payment) monthly.
QRMP scheme taxpayers (turnover up to ₹5 crore, opted for quarterly filing) file GSTR-1 and GSTR-3B quarterly, but still pay tax monthly through a simple challan.
Composition scheme taxpayers file CMP-08 quarterly and GSTR-4 annually.
E-commerce operators, input service distributors, and TDS/TCS deductors have their own separate returns (GSTR-8, GSTR-6, GSTR-7).

Get this classification right first — filing the wrong return, or filing on the wrong schedule, creates compliance headaches that are far more annoying to fix than to avoid.

The Monthly Rhythm (For Regular Taxpayers)

If you’re a regular monthly filer, your GST calendar repeats the same pattern every single month:

11th of the month — GSTR-1 due (details of outward supplies/sales for the previous month)
13th of the month — GSTR-1 due for QRMP taxpayers filing under IFF, and GSTR-6 for Input Service Distributors
20th of the month — GSTR-3B due for taxpayers not under QRMP, and GSTR-5/5A for non-resident taxpayers and OIDAR service providers
22nd of the month — GSTR-3B due for QRMP taxpayers in Category X states (mainly southern and western states)
24th of the month — GSTR-3B due for QRMP taxpayers in Category Y states (mainly northern and eastern states)

If that sounds like a lot to track, that’s because it is — which is exactly why a lot of businesses end up outsourcing this to someone whose entire job is remembering it for them.

Month-by-Month Calendar for 2026

Here’s how the annual cycle typically plays out. (Always cross-check exact dates on the GST portal closer to the month, since government notifications occasionally shift a deadline by a few days.)

January — GSTR-3B for December (20th), GSTR-1 for December (11th), CMP-08 for Oct–Dec quarter (18th)

February — GSTR-3B for January (20th), GSTR-1 for January (11th)

March — GSTR-3B for February (20th), GSTR-1 for February (11th)

April — GSTR-3B for March (20th), GSTR-1 for March (11th), GSTR-4 annual return for composition taxpayers (30th), CMP-08 for Jan–Mar quarter (18th)

May — GSTR-3B for April (20th), GSTR-1 for April (11th)

June — GSTR-3B for May (20th), GSTR-1 for May (11th)

July — GSTR-3B for June (20th), GSTR-1 for June (11th), CMP-08 for Apr–Jun quarter (18th)

August — GSTR-3B for July (20th), GSTR-1 for July (11th)

September — GSTR-3B for August (20th), GSTR-1 for August (11th)

October — GSTR-3B for September (20th), GSTR-1 for September (11th), CMP-08 for Jul–Sep quarter (18th)

November — GSTR-3B for October (20th), GSTR-1 for October (11th)

December — GSTR-3B for November (20th), GSTR-1 for November (11th), GSTR-9 (Annual Return) and GSTR-9C (Reconciliation Statement) for the previous financial year — typically due 31st December

That last one deserves its own callout, because it’s the deadline businesses forget most often.

Don’t Sleep on the Annual Return

GSTR-9 is the annual return every regular taxpayer above the prescribed turnover threshold must file, consolidating the entire year’s monthly/quarterly filings into one document. If your turnover crosses the applicable limit, you’ll also need GSTR-9C, a reconciliation statement comparing your books with your GST returns — this one typically needs certification and is where discrepancies from the year tend to surface.

Because this deadline falls once a year (usually end of December), it’s easy to lose track of amid the routine monthly filings. Businesses that keep clean, reconciled books through the year find this far less painful than those trying to piece together twelve months of data in a rush.

What Happens If You Miss a Deadline

Missing a GST return deadline isn’t a quiet, victimless delay — it comes with real costs:

Late fee: Charged per day of delay for GSTR-3B and GSTR-1, separately under CGST and SGST, until you file.
Interest: 18% per annum on the outstanding tax liability, calculated from the day after the due date.
Input tax credit blockage: Late filing can affect your buyers’ ability to claim input tax credit on invoices you’ve filed late, which damages business relationships even if you eventually pay up.
E-way bill and compliance rating impact: Repeated late filing can restrict your ability to generate e-way bills and affects your GST compliance rating, which vendors and banks sometimes check.

None of these penalties are dramatic on their own, but they compound — a habit of late filing quietly erodes cash flow and credibility over a year.

A Few Practical Habits That Actually Help

Set calendar reminders a week before each due date, not on the day itself — this gives you a buffer to fix invoice mismatches.
Reconcile GSTR-2B with your purchase records monthly, rather than waiting for year-end, so input tax credit claims don’t get disputed later.
File GSTR-1 even if there’s no business activity that month — a NIL return is still mandatory and skipping it invites penalties.
Keep a separate folder for e-invoices and e-way bills so your GSTR-1 filing isn’t a last-minute document hunt.

The Bottom Line

GST return deadlines aren’t complicated once you know your filing category and build the monthly rhythm into your routine — the trouble almost always comes from treating each due date as a surprise instead of a recurring fixture. But between running daily operations, managing invoices, and keeping an eye on GSTR-1, GSTR-3B, and the year-end GSTR-9/9C, most business owners simply don’t have the bandwidth to track twelve months of shifting dates without missing one.

That’s exactly where JSR Taxes Mentor (JSR Taxes) steps in. We handle end-to-end GST return filing for businesses across Delhi NCR — from monthly GSTR-1 and GSTR-3B filings to quarterly CMP-08 returns and the annual GSTR-9/9C reconciliation — so you never have to worry about a late fee, blocked input tax credit, or a compliance rating hit. Our team tracks every due date, reconciles your GSTR-2B against your purchase records proactively, and keeps your filings audit-ready throughout the year, not just in December.

If GST compliance feels like one more thing competing for your attention, let JSR Taxes take it off your plate. Get in touch with our GST filing experts for a free consultation, and turn your GST calendar from a recurring stress point into something you never have to think about again.