By Taxabide 01 Oct 2026

GSTR-3B Filing in October 2026: Due Dates, Late Fees & How to File

Published: October 1, 2026
Last Updated: October 1, 2026

Quick Answer

GSTR-3B Filing October 2026 mainly concerns the return for the September 2026 tax period for monthly filers. Under the standard GST framework, monthly GSTR-3B is due on the 20th of the following month. Taxpayers under the QRMP scheme file quarterly GSTR-3B, with the applicable due date depending on their state or Union Territory group. Uttarakhand is included in the group with a 24th-of-the-following-month due date.

GSTR-3B is a summary GST return used to report applicable GST liability and eligible input tax credit and to discharge the tax payable.

Important: Due dates can be extended through government notifications. Before filing, taxpayers should check the official GST Portal for any notification or advisory applicable to the relevant tax period.

Key Takeaways

  • Monthly GSTR-3B for September 2026 follows the standard 20 October 2026 due date.

  • QRMP taxpayers file GSTR-3B quarterly.

  • Uttarakhand is in the QRMP group with a 24th-of-the-following-month due date.

  • GSTR-3B includes GST liability and eligible ITC information.

  • Late filing can result in late fees.

  • Delayed payment of tax can also result in applicable interest.

  • Sales, purchases, and ITC should be reconciled before filing.

  • Always check the GST Portal for any updated notification before relying on a scheduled date.

What Is GSTR-3B?

GSTR-3B is a summary GST return filed electronically by registered taxpayers who are required to furnish it. It is used to declare applicable tax liability and eligible input tax credit for the relevant tax period and to pay the tax due.

The return can include details relating to outward taxable supplies, reverse-charge liabilities, eligible ITC, tax payable and tax paid.

The GST Council has explained that the standard monthly due date framework is the 20th day of the following month, while different classes of taxpayers may be assigned different due dates.

GSTR-3B Filing October 2026: Due Date

The applicable date depends on whether your business files GSTR-3B monthly or under the QRMP scheme.

Taxpayer category

Relevant period

Standard due-date framework

Monthly GSTR-3B filer

September 2026

20 October 2026

QRMP taxpayer – applicable 22nd group

July–September 2026

22 October 2026

QRMP taxpayer – applicable 24th group

July–September 2026

24 October 2026

The GST Council's published QRMP framework places Uttarakhand in the 24th-date group.

GSTR-3B Due Date for Uttarakhand

For a taxpayer in Uttarakhand filing GSTR-3B under the QRMP quarterly framework, the published due-date structure places the quarterly return on the 24th of the month following the quarter.

For monthly filers, the standard statutory framework is the 20th of the following month.

Before publishing or filing for October 2026, verify whether any specific government notification has extended or changed the applicable date.

What Details Are Reported in GSTR-3B?

Before submitting the return, businesses should reconcile the figures that will be reported.

Depending on the taxpayer and transactions, relevant information can include:

  • Outward taxable supplies

  • Zero-rated supplies

  • Exempt and nil-rated supplies

  • Inward supplies liable to reverse charge

  • Eligible input tax credit

  • ITC reversals

  • CGST, SGST/UTGST and IGST liability

  • Interest and other applicable amounts

  • Tax payment details

The GST return should be prepared from properly reconciled business records rather than estimated figures.

How to File GSTR-3B Online

Step 1: Log in to the GST Portal

Open the official GST Portal and log in with your GST credentials.

Step 2: Select GSTR-3B

Go to the Returns section and select GSTR-3B for the relevant tax period.

For a monthly taxpayer filing in October 2026, the relevant return period is generally September 2026.

Step 3: Reconcile Sales and GST Liability

Check your sales invoices, books, and GST records. Make sure the taxable value and GST liability reported in the return agree with your records.

Step 4: Review Input Tax Credit

Check eligible ITC and review the relevant purchase records and GSTR-2B before claiming credit.

Step 5: Check Reverse-Charge Liability

If your business has transactions covered by reverse charge, make sure the applicable liability has been considered.

Step 6: Review the Return

Before submitting, check:

  • Taxable turnover

  • GST liability

  • ITC

  • ITC reversals

  • Reverse-charge liability

  • Interest, if applicable

  • Tax already paid

Step 7: Pay and File

Pay the applicable tax and other amounts through the GST system and complete the GSTR-3B filing using the applicable authentication method.

GSTR-3B Late Fee in October 2026

Late filing of GSTR-3B can result in a late fee under the applicable GST provisions.

CBIC guidance has stated a late-fee framework of ₹50 per day where the tax liability is not Nil and ₹20 per day where the tax liability is Nil, subject to applicable statutory limits and subsequent notifications.

Therefore, the actual amount should be checked according to:

  • Number of days of delay

  • Whether the return has tax liability

  • Applicable statutory limits

  • Any government notification providing relief or waiver

Do not assume that a late return is automatically free of late fees.

GSTR-3B Interest on Late Tax Payment

Late filing and late payment are not the same issue.

Where GST remains payable beyond the applicable date, interest may become applicable under the GST law. The actual calculation depends on the tax liability, applicable provisions, and period of delay.

Businesses should therefore calculate their GST liability before the due date instead of waiting until the final day.

Can You File a Nil GSTR-3B?

A Nil GSTR-3B may be applicable where there are no reportable transactions or liabilities requiring declaration.

However, no sales does not automatically mean a Nil GSTR-3B.

Before filing a Nil return, check whether there are:

  • Purchases or other inward supplies

  • Reverse-charge transactions

  • ITC-related entries

  • Other reportable liabilities

The taxpayer should confirm that the return genuinely qualifies as Nil before submitting it.

Common GSTR-3B Filing Mistakes to Avoid

Filing without reconciling sales

Differences between books, invoices and GST records can create compliance issues.

Claiming incorrect ITC

Do not claim ITC simply because an invoice is available. Check whether the credit is eligible under the applicable GST provisions.

Ignoring reverse charge

Applicable reverse-charge transactions should be considered before finalising the return.

Confusing GSTR-1 with GSTR-3B

GSTR-1 and GSTR-3B serve different reporting purposes. GSTR-3B is a summary return used for reporting applicable liability and ITC and discharging tax.

Waiting until the last day

Last-minute filing can leave less time to resolve reconciliation, payment, or portal-related issues.

Assuming every taxpayer has the same due date

Monthly and QRMP taxpayers follow different filing frameworks. QRMP due dates can also differ according to the applicable state or Union Territory group.

GSTR-3B Filing for Small Businesses

Small businesses can make GST compliance easier by following a fixed monthly checklist:

Sales → Purchase invoices → GSTR-2B/ITC review → Reverse charge → GST liability → Tax payment → GSTR-3B filing → Acknowledgement

Keeping these records updated throughout the month reduces the need for last-minute reconciliation.

Businesses that need professional assistance can explore TaxAbide's GST Return Filing service.

For more information about the firm, visit the About Us page or use the Contact Us page.

GSTR-3B Filing in Dehradun

Businesses in Dehradun follow the applicable GST framework for registered taxpayers in India.

However, local businesses may still need assistance with:

  • GST return preparation

  • ITC reconciliation

  • Reverse-charge transactions

  • Tax liability calculation

  • Timely return filing

  • GST compliance records

If your business has a large number of invoices or regular ITC and reverse-charge transactions, preparing the return in advance can make the filing process easier.

TaxAbide provides GST return filing support for businesses and taxpayers through its GST Return Filing service.

Official Sources for GSTR-3B Compliance

The GST Council has documented the standard GSTR-3B due-date framework and the different due dates applicable to certain classes of taxpayers.

CBIC has also published guidance explaining the applicable late-fee framework for delayed GSTR-3B filing.

For the latest October 2026 filing status, taxpayers should verify the relevant return period on the official GST Portal and check for any new notification, extension, or technical advisory.

Final Takeaway

GSTR-3B Filing October 2026 requires taxpayers to identify the correct filing category, reconcile their GST records, and submit the return within the applicable deadline.

For monthly filers, the standard framework places the September 2026 GSTR-3B due date on 20 October 2026. For QRMP taxpayers, the due date depends on the applicable state group; Uttarakhand is included in the 24th-date group under the published QRMP framework.

Before filing, reconcile sales, purchases, ITC and tax liability. Most importantly, check the official GST Portal for any October 2026 notification or extension before treating a scheduled date as final.

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Frequently Asked Questions

For monthly taxpayers, the standard framework places the September 2026 GSTR-3B due date on 20 October 2026. Different due dates can apply to certain taxpayer categories.

Under the published QRMP framework, Uttarakhand is included in the group with a 24th-of-the-following-month quarterly GSTR-3B due date.

Late filing can result in a late fee. If tax remains unpaid beyond the applicable date, interest may also become applicable under GST provisions.

Yes, a Nil GSTR-3B may be applicable when there are no reportable transactions or liabilities. However, businesses should first check purchases, reverse-charge transactions, ITC and other applicable entries.

Businesses can get professional assistance through TaxAbide's GST Return Filing service.