October 2026 GST deadlines at a glance
- 11 Oct — GSTR-1 (monthly) for September.
- 13 Oct — Quarterly GSTR-1 (QRMP) for Jul–Sep, plus GSTR-5 & GSTR-6.
- 18 Oct — CMP-08 for composition taxpayers (Jul–Sep).
- 20 Oct — GSTR-3B (monthly) for September — the big one for most businesses.
- 22 Oct — Quarterly GSTR-3B (QRMP) for Jul–Sep (Category X states).
October is a heavy GST month — it carries the September monthly returns and the July–September quarterly returns together. Miss a date and late fees plus interest start ticking immediately. Here's the full calendar, grouped by due date, with a plain-English note on who each return is for.
Full due-date calendar — October 2026
| Due date | Return | Who files it / period |
|---|---|---|
| 10 Oct | GSTR-7 | TDS deductors under GST — September 2026 |
| 10 Oct | GSTR-8 | E-commerce operators collecting TCS — September 2026 |
| 11 Oct | GSTR-1 | Monthly filers — outward supplies for September 2026 |
| 13 Oct | GSTR-1 (QRMP) | Quarterly filers under QRMP — Jul–Sep 2026 |
| 13 Oct | GSTR-5 | Non-resident taxable persons — September 2026 |
| 13 Oct | GSTR-6 | Input Service Distributors (ISD) — September 2026 |
| 18 Oct | CMP-08 | Composition taxpayers — statement-cum-challan for Jul–Sep 2026 |
| 20 Oct | GSTR-3B | Monthly filers — summary return & tax payment for September 2026 |
| 20 Oct | GSTR-5A | OIDAR service providers — September 2026 |
| 22 Oct | GSTR-3B (QRMP) | Quarterly filers, Category X states/UTs — Jul–Sep 2026 |
| 24 Oct | GSTR-3B (QRMP) | Quarterly filers, Category Y states/UTs — Jul–Sep 2026 |
QRMP: why 22 vs 24 October?
Quarterly GSTR-3B has two due dates by state. Category X (mainly southern and western states/UTs — e.g. Maharashtra, Karnataka, Tamil Nadu, Telangana, Andhra Pradesh, Gujarat, Kerala, Goa, MP, Chhattisgarh and nearby UTs) files by 22 October. Category Y (the rest — e.g. UP, Delhi, Rajasthan, Punjab, Bihar, West Bengal, and northern/eastern states) files by 24 October. QRMP taxpayers also pay monthly tax via PMT-06 for the first two months of the quarter.
What each return is — quick reference
Which ones apply to you?
Most regular businesses file GSTR-1 and GSTR-3B — monthly if turnover is above the QRMP limit or you've opted for monthly filing, quarterly under QRMP otherwise. Composition dealers file CMP-08 now and GSTR-4 annually. The specialised returns (GSTR-5/5A/6/7/8) apply only if you're a non-resident, OIDAR provider, ISD, TDS deductor or e-commerce operator. If you're unsure which bucket you fall in, that's worth confirming before the 20th.
Late filing costs add up fast
Missing GSTR-3B or GSTR-1 attracts late fees per day (CGST + SGST) plus 18% interest on any tax paid late — and a delayed GSTR-1 can hold up your buyers' input tax credit, which strains relationships. File even a nil return on time. Also note: GSTR-3B for a period can't be filed until that period's GSTR-1 is filed, so don't leave GSTR-1 to the last minute.
Don't want to track these every month?
efiletax files your GST returns accurately and on time — GSTR-1, GSTR-3B, CMP-08 and the rest — so you never chase a deadline again.
Let efiletax handle itDisclaimer: This calendar is general information for AY/return periods indicated and is current as at the date of publication. Due dates can be extended or changed by CBDT/CBIC notification, and some dates shift when they fall on a holiday — always verify the current date on the GST portal before filing. Not legal or tax advice; talk to efiletax for help with your filings.