GSTR-3B Due Dates 2026: Complete Filing Calendar

Missing a GSTR-3B deadline is one of the most avoidable ways a business ends up paying late fees and interest. The dates themselves aren't complicated once laid out clearly — the confusion usually comes from not knowing which category you fall into: monthly filer, or QRMP quarterly filer under Category X or Category Y states.

This guide lays out the complete GSTR-3B filing calendar for 2026, broken down by filer type, with separate tables so you can find your exact due date without digging through notifications.

What Is GSTR-3B?

GSTR-3B is a self-declared summary return that reports a business's sales, Input Tax Credit (ITC) claimed, and net GST liability for a tax period. It has to be filed by every regular GST-registered taxpayer, even if there were no transactions during that period — a Nil return is still mandatory.

Unlike GSTR-1, which reports invoice-level details, GSTR-3B only requires consolidated totals. It's also the return through which actual tax payment is made, which is why missing its due date triggers both a late fee and interest on the outstanding tax.

Who Files Monthly vs. Quarterly?

Your filing frequency depends on turnover and scheme selection, not on any manual choice each month:

• Monthly filing is mandatory for businesses with aggregate annual turnover above ₹5 crore, and for smaller businesses that haven't opted into the QRMP scheme.

• Quarterly filing (QRMP) is available to businesses with aggregate annual turnover up to ₹5 crore that have opted into the Quarterly Return Monthly Payment scheme. GSTR-3B is filed quarterly, but tax still needs to be paid monthly through Form PMT-06.

GSTR-3B Due Dates for Monthly Filers (FY 2026–27)

Note: These are standard due dates under the general rule (20th of the following month). The CBIC does occasionally extend deadlines — for instance, the due date for March 2026 GSTR-3B was extended from 20 April 2026 to 21 April 2026 via Notification No. 01/2026–Central Tax. Always cross-check the GST portal for extension notifications close to a deadline.

GSTR-3B Due Dates for QRMP (Quarterly) Filers, by State Category

QRMP filers submit GSTR-3B quarterly, and the exact due date depends on whether your principal place of business falls under Category X or Category Y states.

Category X States/UTs (Due Date: 22nd of the month after the quarter)

Chhattisgarh, Madhya Pradesh, Gujarat, Maharashtra, Karnataka, Goa, Kerala, Tamil Nadu, Telangana, Andhra Pradesh, Daman and Diu, Dadra and Nagar Haveli, Puducherry, Andaman and Nicobar Islands, Lakshadweep

Category Y States/UTs (Due Date: 24th of the month after the quarter)

Himachal Pradesh, Punjab, Uttarakhand, Haryana, Rajasthan, Uttar Pradesh, Bihar, Sikkim, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Assam, West Bengal, Jharkhand, Odisha, Delhi, Jammu and Kashmir, Ladakh, Chandigarh

QRMP Quarterly Due Dates for FY 2026–27

Monthly Tax Payment for QRMP Filers (Form PMT-06)

Even though GSTR-3B is filed quarterly under QRMP, tax still has to be deposited every month using Form PMT-06, by the 25th of the following month — for the first two months of each quarter. The third month's liability is settled when the quarterly GSTR-3B itself is filed.

Late Fees for Missing GSTR-3B Deadlines

In addition to the late fee, interest at 18% per annum applies on any outstanding tax amount from the day after the due date until it's actually paid. If tax was paid on time but the return itself was filed late, both the late fee and applicable interest still apply.

What Happens If You Miss the Deadline

• Late fee starts accruing daily from the day after the due date, whether or not there's any tax liability.

• Interest at 18% per annum applies to any unpaid tax amount.

• ITC and compliance ripple effects — a late GSTR-3B can delay your GSTR-2B reconciliation cycle, and repeated late filing can affect your GST compliance rating, which some vendors and clients check before onboarding.

• Three-year filing bar — GSTR-3B cannot be filed after three years from its original due date, and once this window closes, that tax period is permanently blocked from filing.

Common Reasons Businesses Miss GSTR-3B Deadlines

• Confusing the QRMP quarterly filing date with the standard monthly 20th deadline

• Not tracking the separate PMT-06 monthly payment deadline while filing quarterly

• Waiting until the last day to reconcile GSTR-2B with the purchase register, leaving no buffer if mismatches turn up

• Relying on memory or generic calendar reminders instead of return-specific tracking

• Missing state-category-specific QRMP due dates (22nd vs. 24th) when managing clients across multiple states

How to Stay on Top of GSTR-3B Deadlines

• Maintain a return-specific compliance calendar rather than a generic one, especially if you're a CA firm tracking due dates across multiple client GSTINs and states

• Complete GSTR-2B reconciliation well before the due date, not on the day of filing — this avoids last-minute scrambling over mismatches

• Set separate reminders for PMT-06 payments if you're on QRMP, since this is a different deadline from the quarterly return itself

• Always verify the due date on the GST portal close to filing, since CBIC extensions do happen and aren't always widely publicized in advance

Final Thoughts

GSTR-3B deadlines aren't complicated in isolation — the confusion comes from juggling different rules for monthly filers, QRMP quarterly filers by state category, and the separate PMT-06 payment schedule. Once mapped out clearly, as in the tables above, it becomes a matter of building the right reminders and reconciliation habits around them, rather than tracking dates from memory each month.