Form 1 Filing by Stock Exchanges for Client Code Modifications – August 2026

Stock exchanges are required to furnish a monthly statement in Form No. 1 under the Income-tax Rules, 2026, reporting transactions where client codes have been modified after the transactions were registered in the exchange system. For transactions relating to August 2026, the due date for filing the statement is 15 September 2026.

What is Form No. 1?

Form No. 1 is a mandatory monthly statement prescribed under Rule 4 of the Income-tax Rules, 2026.

As clarified by the Income Tax Department, Form No. 1 replaces the earlier Form No. 3BB under Rule 6DDA of the Income-tax Rules, 1962. The corresponding statutory provision is now Section 66(33) of the Income-tax Act, 2025. 

The statement is required in respect of transactions where the client code has been modified after the transaction was registered in the system.

Who is Required to File?

The compliance obligation applies to a stock exchange within the meaning of Section 2(92) of the Income-tax Act, 2025.

The Income Tax Department's FAQ specifically confirms that Form No. 1 is mandatory for stock exchanges and covers transactions in both:

• Cash market; and

• Derivative market.

The form is required to be furnished online through the Income Tax e-filing system. 

Reporting Requirement for Client Code Modifications

The reporting framework is intended to ensure that transactions registered in the exchange system remain properly identifiable and traceable.

Under Rule 4 of the Income-tax Rules, 2026, the relevant stock exchange is required to:

• Record and maintain client particulars, including the unique client identity number and PAN;

• Maintain a complete audit trail of transactions in the cash and derivative markets for seven tax years;

• Ensure that registered transactions are not erased;

• Permit modification of transactions only in cases of genuine error; and

• Maintain information relating to modified transactions and furnish Form No. 1 to the Director General of Income-tax (Systems). 

Due Date for August 2026

Form No. 1 is required to be furnished within 15 days from the last day of the month to which the statement relates. The official Income Tax Department FAQ confirms this filing timeline. 

Accordingly:

• Reporting month: August 2026

• Last day of reporting month: 31 August 2026

• Due date: 15 September 2026

• Form: Form No. 1

• Applicable Rules: Rule 4, Income-tax Rules, 2026

• Relevant Act provision: Section 66(33), Income-tax Act, 2025

The September 2026 compliance calendars published by professional tax resources also list 15 September 2026 as the due date for the August 2026 Form No. 1 filing. 

Practical Compliance Checklist

Stock exchanges should ensure that, before filing Form No. 1:

1. All client-code modifications made during August 2026 are identified.

2. The original and modified transaction details are reconciled.

3. The reason for each modification is appropriately documented.

4. Client identification and PAN details are correctly maintained.

5. Cash and derivative market transactions are appropriately covered.

6. The prescribed Form No. 1 is filed electronically within the statutory deadline.

7. Supporting records and audit trails are preserved for the prescribed period.

Conclusion

Form No. 1 represents an important information-reporting mechanism under the new Income-tax Act, 2025 and Income-tax Rules, 2026. Stock exchanges should ensure that client-code modifications are supported by genuine-error documentation and that the monthly statement for August 2026 is filed by 15 September 2026.

For expert guidance on this topic, contact your tax professional today.

EXCERPT: Form No. 1 for August 2026 client-code modifications is due by 15 September 2026 under Rule 4 of the Income-tax Rules, 2026.

SEO_TITLE: Form 1 Client Code Modification Due Date 2026

SEO_DESCRIPTION: Learn Form 1 requirements and the 15 September 2026 due date for August client-code modifications. Ensure timely compliance—consult your tax professional.