GST Compliance Calendar for October 2026: Important Due Dates and Filing Guide

If your business is registered under GST, October is a month worth planning for in advance. Monthly returns for September are due during the month, and businesses following the quarterly filing scheme also need to complete their July–September compliance.

The difficulty is that not every business follows the same filing schedule. A trader filing monthly returns has different requirements from a small business registered under the QRMP scheme. E-commerce operators, composition taxpayers and certain other registered persons also have their own filing obligations.

To help you plan ahead, this guide covers the important GST return filing due dates for October 2026, explains which forms apply to different taxpayers and highlights the checks that can help you avoid common filing mistakes.

Whether you run a startup, a manufacturing unit, a restaurant, a cloud kitchen or an online selling business, understanding your GST obligations can make monthly compliance much easier to manage.

GST Due Dates for October 2026

The following dates follow the standard GST filing schedule. Any applicable government extension or change in the rules should take precedence, so check the latest updates on the official GST portal before submitting your returns.

10 October 2026: GSTR-7 and GSTR-8

The first important filing deadline falls on 10 October.

GSTR-7 is filed by persons required to deduct tax at source under GST. GSTR-8, on the other hand, applies to e-commerce operators required to collect tax at source.

If your organisation falls under the GST TDS provisions, check the deductions made during September and ensure that the return reflects the relevant figures. E-commerce operators should reconcile their seller transactions and tax collected before filing GSTR-8.

These forms are not required from every GST-registered business. If neither provision applies to your business, these deadlines may not be relevant to you.

11 October 2026: GSTR-1 for Monthly Filers

GSTR-1 is where regular taxpayers report their outward supplies, including applicable sales invoices, debit notes and credit notes.

For monthly filers, the standard due date for September 2026 is 11 October.

Before filing, go through your sales register and make sure the invoices issued during September have been accounted for. Check customer GSTINs, taxable values and tax amounts, and confirm that any credit notes or amendments have been included where required.

For example, if you issued a credit note to a customer in September but overlooked it while preparing your return, your reported figures may not reflect the actual transactions correctly.

Taking a little time to check these details before submission can save you from having to deal with avoidable corrections later.

13 October 2026: Quarterly GSTR-1, GSTR-5 and GSTR-6

Three different filing requirements fall on 13 October under the standard schedule.

Businesses eligible for the Quarterly Return Monthly Payment (QRMP) scheme generally file GSTR-1 every quarter. For the July–September 2026 quarter, the standard due date is 13 October.

The QRMP scheme can be useful for eligible smaller businesses that prefer quarterly return filing instead of filing GSTR-1 and GSTR-3B every month. However, applicable monthly tax payments and other requirements still need to be followed.

GSTR-5 is generally applicable to non-resident taxable persons registered under GST. GSTR-6 is filed by registered Input Service Distributors to report the distribution of eligible input tax credit.

Each form serves a different purpose. Check your registration category before deciding which returns need to be filed.

18 October 2026: CMP-08 for Composition Taxpayers

Businesses registered under the GST composition scheme generally use CMP-08 to report their quarterly self-assessed tax liability and pay the applicable tax.

For the July–September 2026 quarter, the standard due date is 18 October.

Before submitting the statement, review your turnover for the quarter and calculate the tax payable under the applicable composition provisions. Keep your sales records and payment details ready so that you can complete the process without rushing.

Remember that the composition scheme has different compliance requirements from the regular GST scheme. If your business is registered under the composition scheme, make sure you follow the rules applicable to your category.

20 October 2026: GSTR-3B for Monthly Filers

GSTR-3B is the summary return through which regular taxpayers report their tax liability, eligible input tax credit and applicable tax payments.

For monthly filers, the standard due date for September 2026 is 20 October.

This is a return worth preparing carefully because the figures reported should reflect your actual business transactions and applicable GST liability.

Start by checking the sales figures reported in GSTR-1. Then review your purchase records and GSTR-2B before claiming eligible input tax credit. If an invoice is missing or the figures do not match, investigate the difference rather than assuming the credit can be claimed automatically.

You should also review expenses or purchases that may attract reverse charge, where applicable, and check whether sufficient funds are available to pay the tax liability.

For instance, a business may have purchase invoices recorded in its accounts, but that does not automatically mean every invoice qualifies for ITC. Eligibility must be checked against the applicable GST provisions and supporting records.

A proper review before filing can help reduce errors and make your GST records easier to reconcile.

20 October 2026: GSTR-5A for Applicable OIDAR Service Providers

GSTR-5A applies to specified suppliers of Online Information and Database Access or Retrieval (OIDAR) services under the relevant GST provisions.

Eligible service providers should review their September transactions and applicable tax liability before the standard filing deadline of 20 October.

This return is relevant only to the specified category of service providers. Businesses offering other types of services should check whether the OIDAR provisions apply to their activities before treating this as an applicable filing requirement.

22 October 2026: Quarterly GSTR-3B for QRMP Taxpayers in Category X Jurisdictions

Eligible taxpayers registered under the QRMP scheme generally file GSTR-3B quarterly while making the applicable monthly tax payments.

For the July–September 2026 quarter, the standard due date is 22 October for eligible QRMP taxpayers in the applicable Category X jurisdictions.

These include Odisha, Maharashtra, Gujarat, Karnataka, Kerala, Tamil Nadu, Telangana, Andhra Pradesh, Goa, Chhattisgarh and Madhya Pradesh, along with other jurisdictions specified in the applicable classification.

If your business is registered in one of these locations and you have opted for QRMP, check your filing category and the relevant return period before submitting GSTR-3B.

24 October 2026: Quarterly GSTR-3B for QRMP Taxpayers in Category Y Jurisdictions

The standard quarterly GSTR-3B deadline for eligible QRMP taxpayers in Category Y jurisdictions is 24 October.

These include West Bengal, Rajasthan, Uttar Pradesh, Bihar, Jharkhand, Haryana, Punjab, Uttarakhand and Himachal Pradesh, along with other jurisdictions covered by the applicable classification.

The filing date depends on the relevant jurisdiction category. Businesses should verify their registration details and the applicable deadline rather than relying only on a general GST calendar.

25 October 2026: ITC-04 for Applicable Job-Work Transactions

ITC-04 is used by applicable principal taxpayers to report specified goods sent to or received from job workers under GST.

The standard half-yearly deadline for the April–September 2026 period is 25 October for taxpayers covered by the applicable filing requirement, including relevant principal taxpayers whose aggregate turnover exceeded ₹5 crore in the preceding financial year, subject to the applicable rules.

This requirement may be relevant to manufacturers who send raw materials, components or capital goods to another party for processing or other permitted job-work activities.

If your business uses job workers, keep track of the goods sent, goods received back and the corresponding delivery challans. These records help you establish where the goods are and reconcile their movement with your accounts.

ITC-04 does not apply to every GST-registered business. Check whether your transactions and registration fall within the relevant requirements.

28 October 2026: GSTR-11 for Applicable UIN Holders

GSTR-11 is used by specified persons holding a Unique Identity Number (UIN) to report inward supplies under the relevant GST provisions.

The standard due date for the September 2026 period is 28 October.

This requirement does not apply to ordinary GST-registered businesses. UIN holders should check the applicable reporting requirements and ensure that the information for the relevant period is ready before filing.

What Should You Check Before Filing GST Returns?

Knowing the due dates is useful, but the figures submitted in your returns matter just as much.

Before filing, make sure your sales invoices, purchase bills, credit notes and debit notes are properly recorded. Compare your books with the relevant GST statements and resolve discrepancies wherever possible.

Pay particular attention to input tax credit. Review GSTR-2B, check the relevant purchase invoices and confirm that the credit meets the applicable eligibility conditions. Do not claim credit simply because an expense appears in your accounting records.

You should also calculate the tax payable for the period, review any applicable reverse charge transactions and check your electronic cash and credit ledger balances.

Finally, confirm that you are using the correct return form and filing period. A monthly taxpayer and a taxpayer under the QRMP scheme may have different deadlines, even when they are dealing with the same type of return.

What Happens If You Miss a GST Due Date?

Missing a GST deadline can lead to late fees, interest on delayed tax payments or other consequences under the applicable GST provisions.

The amount payable depends on the type of return, the tax liability, the period of delay and the relevant rules. The same late-fee or interest calculation does not necessarily apply to every GST form.

Delayed filing can also create practical problems. For example, a difference between your purchase records and supplier-reported information may require further reconciliation before you can determine the eligible input tax credit.

If you have missed a deadline, identify the outstanding return, calculate the applicable liability and complete the required compliance steps as soon as possible.

Keeping a regular filing schedule is generally easier than dealing with several overdue returns at once.

GST Compliance Tips for Small Businesses and MSMEs

For a small business, GST filing is often one of several responsibilities handled alongside sales, purchasing, customer service and daily operations. A simple record-keeping routine can make a real difference.

Keep your invoices organised by month instead of collecting everything at the end of the quarter. Review purchase records regularly and follow up on missing invoices or incorrect GSTINs. If you sell through online marketplaces, make sure you understand the GST reporting requirements that apply to your business model.

It is also worth setting reminders for your applicable filing dates. Do not assume that every GST-registered business follows the same calendar, and remember that official notifications may change a standard due date.

Most importantly, review the figures before filing. Correcting an error during preparation is usually easier than dealing with the consequences after submission.

How E-Incorp Elite Can Help With GST Compliance

Understanding GST requirements is easier when you know which rules apply to your business and what needs to be done before each deadline.

E-Incorp Elite provides GST-related services, including GST registration, GST return filing, GST cancellation and related business compliance assistance.

Whether you operate a startup, trading business, manufacturing unit, restaurant, cloud kitchen or online selling business, identifying your applicable GST requirements is an important step towards maintaining organised business records.

If you need assistance with GST registration, return filing or understanding your business's compliance requirements, visit www.e-incorpelite.com to learn more about our services.

Frequently Asked Questions About GST Due Dates in October 2026

What are the important GST due dates for October 2026?

The standard calendar includes GSTR-7 and GSTR-8 on 10 October, monthly GSTR-1 on 11 October, quarterly GSTR-1 on 13 October, CMP-08 on 18 October, monthly GSTR-3B and GSTR-5A on 20 October, quarterly GSTR-3B on 22 or 24 October, applicable ITC-04 on 25 October and GSTR-11 on 28 October. Other requirements may apply to specific taxpayer categories.

What is the GSTR-1 due date for October 2026?

The standard due date for monthly GSTR-1 for September 2026 is 11 October. Eligible QRMP taxpayers filing for the July–September quarter generally have a due date of 13 October.

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

For regular monthly filers, GSTR-3B for September 2026 is generally due on 20 October. Eligible QRMP taxpayers filing for the July–September quarter generally have a due date of 22 or 24 October, depending on the applicable jurisdiction category.

Who needs to file CMP-08?

Eligible taxpayers registered under the GST composition scheme generally file CMP-08 quarterly to report their self-assessed tax liability and pay the applicable tax.

What is the difference between GSTR-1 and GSTR-3B?

GSTR-1 reports details of outward supplies, while GSTR-3B is a summary return used to report applicable tax liabilities, eligible input tax credit and tax payments.

Can small businesses file GST returns quarterly?

Eligible taxpayers may opt for the QRMP scheme if they satisfy the prescribed conditions. The scheme generally allows quarterly GSTR-1 and GSTR-3B filing, with applicable monthly tax payments.

Is GST return filing required if there are no sales?

A Nil return may still be required if a taxpayer is obligated to file the relevant return for that period. The requirement depends on the taxpayer category and the form concerned.

Where can I check the latest GST filing dates?

Visit the official GST portal at www.gst.gov.in and check the applicable return dashboard, advisories and government notifications for updated filing requirements.

Conclusion

If your business has GST filing obligations in October, take a few minutes to identify the forms that apply to you and the dates you need to meet. Keep your invoices updated, reconcile your figures before filing and check for any official changes to the standard schedule.

A little preparation can help you manage GST compliance with fewer last-minute problems and keep your business records in better order.

For GST registration, GST return filing and related compliance assistance, visit E-Incorp Elite at www.e-incorpelite.com.

Disclaimer: This article is intended for general information and awareness. GST due dates and filing requirements may change through government notifications. Verify the latest official guidance and the applicability of each form before filing.