Unique Document Identification Number: Frequently Asked Questions 

To begin

The UDIN (Unique Document Identification Number) is an initiative introduced by the Institute of Chartered Accountants of India (ICAI) to prevent misuse of certificates and reports issued by Chartered Accountants. Over the years, authorities faced several issues due to forged documents signed by non-CAs posing as Chartered Accountants. UDIN was introduced to address this issue and bring traceability and accountability to every certified document.

In this article, we have answered the most frequently asked questions about UDIN in a clear and practical manner.

1. What is Unique Document Identification Number (UDIN)?

Unique Document Identification Number, commonly known as UDIN, is an 18-digit system-generated unique number. A full-time practicing Chartered Accountant is required to generate UDIN for every document that is certified, attested, or audited by them.

The ICAI conceptualized UDIN after observing repeated instances of fake certifications and forged signatures being submitted to government departments. UDIN enables authorities and stakeholders to verify whether a document has been genuinely issued by a practicing Chartered Accountant.

2. When did UDIN become mandatory?

As per the decision of the ICAI Council, UDIN was implemented in a phased manner as follows:

• UDIN became mandatory for all certificates with effect from 1 February 2019
• UDIN became mandatory for all GST audit reports and tax audit reports with effect from 1 April 2019
• UDIN became mandatory for all other audit, assurance, and attestation functions with effect from 1 July 2019

3. Is UDIN mandatory for uploading audit reports and CA certification forms on e-filing portals?

Yes, quoting UDIN is mandatory while uploading audit reports and CA certification forms on applicable e-filing portals. These portals use UDIN to validate the authenticity of the document and confirm that it has been issued by a practicing Chartered Accountant.

4. Is it possible to upload a form without mentioning UDIN?

Yes, it is possible to upload a form without quoting UDIN at the time of upload. However, the Chartered Accountant must generate and update the UDIN within 15 calendar days from the date of uploading the form. If UDIN is not updated within this time limit, the uploaded form may be treated as invalid.

ICAI advises generating UDIN on the date of signing the document, and the 15-day window should be used only where immediate generation is not possible.

5. What should be done if the form submission page does not open after entering UDIN?

In certain cases, the UDIN validation process may take additional time due to system-related issues. If the form submission page does not open after entering UDIN, the CA may remove the UDIN and proceed with uploading the form. The UDIN can then be updated later, provided it is done within 15 calendar days from the date of upload.

6. A form has been uploaded with a valid UDIN, but the UDIN status shows “Update UDIN”. What does this mean?

This status indicates that the taxpayer has not yet accepted the uploaded form. Until the taxpayer accepts the form, the Chartered Accountant is permitted to modify or update the UDIN details linked to that form.

7. How can UDIN be updated if the form was uploaded without UDIN?

To update UDIN after uploading the form, the following steps must be followed:

• Log in to the relevant e-filing portal
• Navigate to the “My Account” tab
• Click on the option “View/Update UDIN details”
• Enter and update the UDIN for the respective form

This update must be completed within 15 calendar days from the date of uploading the form.

8. How can errors be corrected if UDIN has already been updated in a form?

If an error is identified after uploading the form but before the taxpayer has accepted it, the taxpayer should not accept the form. The corrected form can then be uploaded using the same UDIN, and the taxpayer should accept the corrected version.

9. What if an error is found after the taxpayer has accepted a form with a valid UDIN?

If the taxpayer has already accepted the form and an error is discovered later, the form must be revised. Where revocation of the earlier UDIN is permitted under ICAI rules, the UDIN may be revoked and a revised form uploaded with a freshly generated UDIN. The revised form will be treated as a new submission.

It is important to note that ICAI allows revocation of UDIN only within a limited time period from its generation. If revocation is not permitted, correction can be made only through revision with a new UDIN.

10. What happens if a CA uploads a form without UDIN and fails to update it within 15 days, but the taxpayer accepts the form?

In such cases, the form will be treated as invalid. Acceptance by the taxpayer does not override the requirement of UDIN compliance. Legal consequences applicable under the relevant law may arise due to non-compliance.

11. What happens if a form is uploaded with UDIN but not accepted by the taxpayer?

A form uploaded by a Chartered Accountant will not be considered a valid submission unless it is accepted by the taxpayer. Until acceptance, the submission remains incomplete and does not carry legal validity.

12. What is considered the date of submission of the form by the taxpayer?

The date of submission is considered as the later of the following two dates:

1. The date on which the taxpayer accepts the uploaded form
2. The date on which the Chartered Accountant furnishes the UDIN

13. What happens if a UDIN linked to a form is revoked?

If a UDIN linked to a form is revoked after the taxpayer has accepted the form, the form becomes invalid from the date of revocation. Any legal consequences under the applicable law may arise from that date.

14. What will be the submission date if a form is revised after UDIN revocation?

If a revised form is uploaded with a new UDIN after revoking the earlier one, the date on which the taxpayer accepts the revised form will be treated as the date of submission.

15. How can errors be corrected if UDIN has not yet been updated?

If an error is identified after uploading the form and UDIN has not yet been updated, the taxpayer should not accept the form. The Chartered Accountant can re-upload the corrected form using the same UDIN and ensure that the taxpayer accepts the corrected version.

16. What does the status “Consumed” mean under UDIN status?

The status “Consumed” indicates that the form uploaded with that UDIN has been accepted by the taxpayer. Once consumed, the UDIN cannot be reused for another form or for revising the same form unless it is revoked as per ICAI rules.

17. What does the status “Unconsumed” mean under UDIN status?

The status “Unconsumed” indicates that the form uploaded with that UDIN has been rejected by the taxpayer. In such cases, the same UDIN may be reused for re-uploading the form.

18. How can UDIN be modified if it is linked to a form that is neither accepted nor rejected?

The Chartered Accountant can modify UDIN details by using the “View/Update UDIN details” option available under the “My Account” tab on the e-filing portal. This option remains available until the taxpayer either accepts or rejects the form.

Conclusion

UDIN plays a key role in maintaining transparency and trust in professional documentation. It protects authorities, taxpayers, and Chartered Accountants by ensuring that every certified document is traceable and verifiable.

A clear understanding of UDIN rules, timelines, and portal processes helps avoid document rejection and compliance-related issues.