October 2026 Tax Compliance Calendar: Complete Due Date Guide for Income Tax, GST, TDS & Audit Deadlines
October 2026 stands out as one of the most compliance-intensive months of the financial year. Businesses, employers, GST-registered entities, deductors, collectors, professionals, and composition-scheme taxpayers all face a confluence of monthly filings and quarterly obligations covering the July–September 2026 period. Layered on top of these routine requirements is a critical income-tax development — the extension of the tax audit report deadline under CBDT Circular No. 07/2026 dated 28 September 2026 — making proactive compliance management essential throughout the month.
This calendar provides a date-wise reference guide covering every major compliance event in October 2026. Each entry identifies the applicable return or statement, the period it covers, and the key reconciliation or verification steps recommended before filing.
Important: This guide is a general compliance-control reference. Due dates, filing frequencies, and category-specific obligations vary based on registration profile, turnover, transaction type, and applicable notifications. Always verify the current statutory and portal position before filing or making any payment.
October 2026 Tax Compliance Calendar — Quick Reference Table
| Due Date | Compliance | Period / Particulars |
|---|---|---|
| 7 October 2026 | TDS/TCS Deposit | Tax deducted/collected in September 2026 |
| 10 October 2026 | GSTR-7 | September 2026 — GST TDS return |
| 10 October 2026 | GSTR-8 | September 2026 — GST TCS by applicable e-commerce operators |
| 11 October 2026 | GSTR-1 (Monthly) | September 2026 — monthly filers |
| 13 October 2026 | GSTR-1 (Quarterly/QRMP) | July–September 2026 quarter |
| 13 October 2026 | GSTR-6 | September 2026 — Input Service Distributors |
| 15 October 2026 | Specified Income-tax Statements | Quarter ended 30 September 2026 |
| 18 October 2026 | CMP-08 | July–September 2026 — Composition taxpayers |
| 20 October 2026 | GSTR-3B (Monthly) | September 2026 |
| 20 October 2026 | GSTR-5 / GSTR-5A | September 2026 — applicable non-residents/OIDAR |
| 21 October 2026 | Specified Audit Reports | AY 2026-27 — extended from 30 September 2026 |
| 25 October 2026 | PMT-06 (QRMP) | September 2026 payment, where applicable |
| 28 October 2026 | GSTR-11 | Applicable UIN holders |
| 30 October 2026 | Form 141 | Specified challan-cum-statements — September 2026 |
| 31 October 2026 | Quarterly TDS/TCS Statements | Quarter ended 30 September 2026 |
7 October 2026: TDS and TCS Deposit for September
The first significant deadline of the month falls on 7 October 2026, by which applicable deductors and collectors must deposit tax deducted at source or collected at source in respect of September 2026 transactions. The date is also relevant in cases where the Assessing Officer has granted permission for quarterly TDS deposits in specified circumstances.
Pre-Payment Verification Checklist
Before making the deposit, tax and finance teams should verify the following:
- PAN details and deductee/collectee records
- Correct nature of payment and applicable section of deduction or collection
- Applicable rate of TDS or TCS, including any lower or nil deduction certificate
- Reconciliation of TDS/TCS ledger with underlying challans
- Accuracy of book entries and payment dates
- Potential interest exposure arising from any delayed deduction or deposit
October 2026 holds additional significance because it also marks the opening of the quarterly reporting cycle for the period ended 30 September 2026, meaning TDS teams will simultaneously manage both deposit and filing workflows.
10 October 2026: GSTR-7 and GSTR-8
GSTR-7 — GST TDS Return
Entities required to deduct tax at source under the GST framework should ordinarily furnish GSTR-7 for September 2026 by 10 October 2026. Before filing, deductors should reconcile deductions made against amounts paid to suppliers and confirm that the corresponding tax has been deposited to the government.
GSTR-8 — GST TCS Statement
Applicable e-commerce operators required to collect tax at source under GST should ordinarily file GSTR-8 for September 2026 by 10 October 2026. Operators should reconcile total supplies facilitated through their platform, apply adjustments for returns, and verify the TCS amount before submission.