GST Due Dates for October 2026: Complete Filing Calendar

Last updated: 1 October 2026. October 2026 has nine GST filing dates, because the July–September quarter closes on top of the usual monthly cycle: quarterly GSTR-1 on the 13th, CMP-08 on the 18th, quarterly GSTR-3B on the 22nd or 24th, and the half-yearly ITC-04 on the 25th. Five of the nine fall on a Saturday or Sunday, and Dussehra lands on Tuesday 20 October, the monthly GSTR-3B date. None of those dates moves.

Applicability Note: This guide reflects GST provisions and CBIC notifications applicable as of 1 October 2026. Due dates change through CBIC notifications, and the GST portal is the authoritative source. No October 2026 extension has been notified as of this writing. Always verify on gst.gov.in or with a GST professional before filing.

Who Should Care?

This guide applies to:

• QRMP filers. September is Month 3, so the quarterly GSTR-1 (13 October) and quarterly GSTR-3B (22 or 24 October) both fall this month, and the window to switch for October–December closes on 31 October.
• Composition dealers under Section 10, who pay CMP-08 for July–September by 18 October.
• Monthly filers of GSTR-1 and GSTR-3B, who also have the FY 2025-26 Rule 42 true-up riding on the 20 October return.
• Manufacturers sending goods for job work whose aggregate turnover crossed ₹5 crore in FY 2025-26: ITC-04 for April–September is due 25 October.
• TDS deductors, e-commerce operators, non-resident taxable persons, ISDs, OIDAR providers and UIN holders.

1. October 2026 GST Deadline Calendar at a Glance

Subject to notification changes. Verify on the GST portal before filing.

2. Five Weekend Dates, a Festival, and the Bank Counter

The 10th, 11th, 18th, 24th and 25th all fall on a Saturday or Sunday. No CBIC notification shifts a GST due date for a weekend or holiday, and late fee under Section 47 runs from the day after the due date. The "next working day" rule people quote is Section 10 of the General Clauses Act, 1897, which applies only "if the Court or office is closed on that day or the last day of the prescribed period". The GST portal doesn't close, and we found no CBIC instrument applying Section 10 to return due dates. Our September calendar covers the argument in full.

Where it actually bites: paying at a bank

Under Rule 87(3), you can deposit tax by internet banking, UPI, IMPS, card, NEFT or RTGS, or over the counter at an authorised bank, up to ₹10,000 per challan per tax period. UPI and IMPS were added by Notification No. 14/2022-Central Tax dated 5 July 2022.

Two of October's Saturdays are bank holidays. The Government of India notification dated 20 August 2015 made the second and fourth Saturday of every month public holidays for banks under Section 25 of the Negotiable Instruments Act, 1881, from 1 September 2015 (RBI press release dated 28 August 2015). In October 2026 those are the 10th (GSTR-7 and GSTR-8, both tax-paying) and the 24th (quarterly GSTR-3B for Category II States). Dussehra falls on Tuesday 20 October 2026, the monthly GSTR-3B and GSTR-5A date. Banks in many states close on one or more days between 19 and 21 October; check the RBI holiday list for your state.

If you pay at a counter, plan around it:

• For the 10th, deposit by Friday 9 October.
• For the 18th (CMP-08) and the 20th (GSTR-3B), deposit by Saturday 17 October, a third Saturday, and check your state's list: Durga Puja closures start that weekend in some states, and Monday 19 October is a bank holiday in several.
• For the 24th, deposit by Friday 23 October, and check your state's list.

The 11th (GSTR-1) and 25th (ITC-04) carry no payment. Don't generate a challan weeks early either: under the first proviso to Rule 87(2), a PMT-06 challan is valid for fifteen days.

3. Monthly Filers: 11 and 20 October

Sunday 11 October: GSTR-1 for September 2026

GSTR-1 reports September's outward supplies; the B2B portion feeds your buyers' GSTR-2B on the 14th. GSTR-1A lets you fix the same period's invoices until you file its GSTR-3B.

Tuesday 20 October: GSTR-3B for September 2026, GSTR-5A, and the Rule 42 true-up

The monthly GSTR-3B is due on the 20th in every State under Rule 61(1)(i). Interest at 18% a year runs on the net cash component of a late return under the proviso to Section 50(1). GSTR-5A, filed by overseas OIDAR providers, shares the date but carries the full ₹200-a-day fee (see the table below).

This return has one more job this year. Under Rule 42(2), the annual recalculation of common credit for FY 2025-26 has to be settled by the due date of the return for September 2026, which for monthly filers is 20 October. Our Rule 42 true-up guide has the worked numbers.

4. QRMP Filers: The July–September Quarter Closes

Tuesday 13 October: quarterly GSTR-1

It covers every outward supply from July to September. Invoices already sent through the July and August IFF carry across; September's appear for the first time, because Month 3 has no IFF. A monthly-filing buyer sees them in the September GSTR-2B on 14 October; a QRMP buyer, in the quarterly GSTR-2B generated the same day.

22 or 24 October: quarterly GSTR-3B

The date depends on where your principal place of business is, under Rule 61(1)(ii) and its Table (substituted from 1 January 2021 by Notification No. 82/2020-Central Tax dated 10 November 2020):

• Thursday 22 October (Category I): Chhattisgarh, Madhya Pradesh, Gujarat, Maharashtra, Karnataka, Goa, Kerala, Tamil Nadu, Telangana, Andhra Pradesh, and the UTs of Daman and Diu and Dadra and Nagar Haveli, Puducherry, Andaman and Nicobar Islands and Lakshadweep.
• Saturday 24 October (Category II): Himachal Pradesh, Punjab, Uttarakhand, Haryana, Rajasthan, Uttar Pradesh, Bihar, Sikkim, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Assam, West Bengal, Jharkhand, Odisha, and the UTs of Jammu and Kashmir, Ladakh, Chandigarh and Delhi.

September's tax is paid here, net of the July and August PMT-06 deposits. There is no PMT-06 for September: Rule 61(3) limits the challan to "each of the first two months of the quarter". On the settled practitioner reading, this quarterly return is also where a QRMP filer settles the FY 2025-26 Rule 42 true-up, since Rule 42(2) is written for "the return for the month of September" and a QRMP filer doesn't file one.

Saturday 31 October: last day to switch for October–December

Under Rule 61A(1), the window for October–December 2026 runs 1 August to 31 October. Do nothing and your current choice carries forward. Our QRMP switch guide covers what changes on each side.

5. Composition Dealers: CMP-08 by Sunday 18 October

Rule 62(1)(i) requires the CMP-08 statement for July–September "till the 18th day of the month succeeding such quarter". The GST portal's CMP-08 FAQ is direct: "No, there is no late fee for delayed filing of Form GST CMP-08." Late composition tax still carries 18% interest under Section 50.

6. Job Work: ITC-04 by Sunday 25 October

Since 1 October 2021, Rule 45(3) and its Explanation (inserted by Notification No. 35/2021-Central Tax dated 24 September 2021) split filers in two:

• A principal whose aggregate turnover in the preceding financial year exceeded ₹5 crore files half-yearly. April–September 2026 is due 25 October 2026.
• Everyone else files once a year, due 25 April.

The test is aggregate turnover under Section 2(6), computed PAN-wide for FY 2025-26, and not the AATO figure on your portal dashboard. More in our job work guide.

7. Other Returns in October 2026

Saturday 10 October: GSTR-7 and GSTR-8

GSTR-7 reports TDS under Section 51; its reduced fee and nil-month waiver come from Notification No. 23/2024-Central Tax dated 8 October 2024. GSTR-8 is the e-commerce operator's TCS statement under Section 52, with TCS at 0.5% per Notification No. 15/2024-Central Tax dated 10 July 2024, and no fee reduction. Both are tax-paying, and 10 October is a bank holiday.

Tuesday 13 October: GSTR-5 and GSTR-6

GSTR-5 is for non-resident taxable persons. It has been due on the 13th since 1 October 2022, when Section 39(5) as amended by the Finance Act 2022 came into force through Notification No. 18/2022-Central Tax dated 28 September 2022. Older calendars still say the 20th. GSTR-6 is the Input Service Distributor's return for September.

Wednesday 28 October: GSTR-11

UIN holders such as embassies and UN bodies file GSTR-11 for September to claim refunds.

8. Also on the October Radar

• FY 2025-26 closes on 30 November 2026. ITC, credit notes and return corrections for the year stop then, or earlier if you file the annual return first. A credit note goes in the return for its month of issue, so a monthly filer's practical date is 31 October. Our FY 2025-26 cut-off guide sets out which returns are left for monthly and QRMP filers.
• 57th GST Council meeting. Press reports put it on Wednesday 7 October 2026 in New Delhi, with officers meeting on 5 and 6 October, after it was moved from 12 September. A recommendation changes nothing until it is notified.
• New DSC token? Upgrade emSigner. The GSTN advisory dated 19 September 2026 says anyone issued a new DSC token on or after 21 September 2026 must use emSigner version 3.3. Existing tokens that work need no change. Test a new token before the 13th.
• GSTR-9 and GSTR-9C for FY 2025-26 are due 31 December 2026. GSTR-9 is optional up to ₹2 crore aggregate turnover under Notification No. 15/2025-Central Tax dated 17 September 2025; GSTR-9C applies above ₹5 crore under Rule 80(3). See the annual return guide.

9. Late Fee and Interest Summary

All late fees below are total amounts under CGST + SGST combined. Per-Act figures appear in parentheses where useful.

† GSTR-3B caps per Notification No. 19/2021-Central Tax dated 1 June 2021 and GSTR-1 caps per Notification No. 20/2021-Central Tax dated 1 June 2021: aggregate turnover up to ₹1.5 crore → ₹2,000; ₹1.5–5 crore → ₹5,000; above ₹5 crore → ₹10,000; nil returns → ₹500. GSTR-5 fee per Notification No. 5/2018-Central Tax and GSTR-6 per Notification No. 7/2018-Central Tax, both dated 23 January 2018. Interest at 18% per Notification No. 13/2017-Central Tax dated 28 June 2017.

‡ GSTR-5A's reduced fee under Notification No. 6/2018-Central Tax dated 23 January 2018 was rescinded by Notification No. 13/2018-Central Tax dated 7 March 2018. Sources disagree on whether any reduced nil figure survives, so none is stated.

Key Takeaways

• Nine filing dates in October 2026, because the July–September quarter closes: quarterly GSTR-1 (13th), CMP-08 (18th), quarterly GSTR-3B (22nd or 24th) and half-yearly ITC-04 (25th) sit on top of the monthly cycle.
• The 10th, 11th, 18th, 24th and 25th fall on a weekend, and none of them moves. If you pay at a bank counter, deposit by 9 October for the 10th, by Saturday 17 October for the 18th and the 20th, and by 23 October for the 24th.
• Dussehra is Tuesday 20 October, the monthly GSTR-3B date. That return also carries the FY 2025-26 Rule 42 true-up for monthly filers.
• QRMP filers pay no PMT-06 for September; it settles in the quarterly GSTR-3B. The switch window for October–December closes 31 October.
• ITC-04 is half-yearly only above ₹5 crore aggregate turnover in FY 2025-26, tested on the Section 2(6) figure rather than the dashboard AATO.
• CMP-08 has no late fee, but late composition tax still carries 18% interest.

Frequently Asked Questions

What is the GSTR-3B due date for September 2026?

Monthly filers must file by Tuesday 20 October 2026 in every State. QRMP filers file the July–September quarterly GSTR-3B by 22 October (Category I States/UTs) or 24 October (Category II), under Rule 61(1)(ii). 20 October is Dussehra, and the date does not move.

When is the quarterly GSTR-1 due for July–September 2026?

Tuesday 13 October 2026, under Notification No. 83/2020-Central Tax dated 10 November 2020. September invoices appear for the first time here, because Month 3 of a quarter has no IFF.

Is there a late fee for filing CMP-08 late?

No. The GST portal's CMP-08 FAQ says "there is no late fee for delayed filing of Form GST CMP-08." Interest at 18% a year under Section 50 still applies to composition tax paid after 18 October 2026.

Is ITC-04 due in October 2026?

Only if your aggregate turnover in FY 2025-26 exceeded ₹5 crore. Then the April–September 2026 return is due 25 October 2026 under Rule 45(3). Below that, ITC-04 is annual and the FY 2026-27 return is due 25 April 2027.

Do GST due dates move if they fall on a Sunday or Dussehra?

No. No CBIC notification shifts a GST due date for a weekend or holiday, and Section 10 of the General Clauses Act applies only where the office is closed. The portal stays open; the bank counter doesn't.

⚠️ For informational purposes only.

Have a question about your October filings or the quarter-close returns? Ask our GST experts → gstconsultancy.com