What is UDIN? Everything You Need to Know About UDIN Number   

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If you have ever submitted a document certified by a Chartered Accountant, you may have noticed a long number mentioned on it. Many people ignore it or do not ask questions about it. That number is called UDIN. At Ebizfiling, clients often ask us what UDIN means, why it is required, and whether their document is valid without it.

This blog explains what is UDIN, why it exists, and how it affects businesses, in the simplest way possible.

What is UDIN?

UDIN stands for Unique Document Identification Number.
UDIN is a unique number generated by a Chartered Accountant for every certificate, report, or document they sign. This number is generated through the official ICAI UDIN portal and is linked to a specific document.

In simple words, a UDIN proves that a document is genuine and issued by a real Chartered Accountant.

Why was UDIN introduced?

Before UDIN was introduced, there were many cases where fake certificates and reports were submitted using forged CA signatures. Government departments had no easy way to verify whether a document was actually issued by a Chartered Accountant.

To solve this problem, the Institute of Chartered Accountants of India (ICAI) introduced UDIN.

The purpose of UDIN is to:

• Prevent misuse of CA signatures
• Stop fake or forged certificates
• Make document verification simple
• Increase trust and transparency

Today, UDIN has become an important part of compliance in India.

Is UDIN mandatory?

Yes, UDIN is mandatory for most CA-certified documents.

If a document requires UDIN and it is not mentioned, the document may be rejected by tax authorities, GST officers, banks, or other government departments. Many departments now accept CA documents only if a valid UDIN number is mentioned.

What kind of documents require UDIN?

UDIN is required for almost all documents signed or certified by a Chartered Accountant, such as:

• Tax audit reports
• Form 3CEB
• Form 3CD
• Net worth certificates
• Turnover certificates
• Valuation reports
• GST audit and certification reports

If a Chartered Accountant signs the document, UDIN usually applies.

Who generates the UDIN?

Only the Chartered Accountant who signs the document can generate the UDIN number. Clients or businesses cannot generate UDIN themselves. The CA logs into the ICAI UDIN portal, enters document details, and generates the UDIN. Once generated, the CA mentions this UDIN number on the document. This ensures accountability and authenticity.

How does UDIN work?

The UDIN process is straightforward. After preparing and signing a document, the Chartered Accountant generates a UDIN by entering basic details such as document type, date, and client information.

The UDIN is then linked permanently to that document. Once generated, the same UDIN cannot be reused for any other document.

New UDIN Disclosure Requirement on DigiCA Platform

The ICAI has introduced a new disclosure requirement while generating UDIN on the DigiCA platform.
Now, at the time of generating UDIN for audit reports, Chartered Accountants are required to provide details of the previous year’s auditor, wherever applicable. This includes confirming whether a No Objection Certificate (NOC) or proper communication has been obtained from the previous auditor, as required under the Code of Ethics.

In simple terms, this step ensures that:

• The previous auditor has been formally informed
• Ethical requirements are followed
• Audit reports are not issued without proper professional communication

This disclosure is captured directly during UDIN generation and helps maintain transparency and professional accountability.

Check UDIN portal for official notification.

How can a UDIN be verified?

One of the biggest advantages of UDIN is easy verification.

Any person or authority can:

• Visit the ICAI UDIN verification portal
• Enter the UDIN number mentioned on the document
• Check the document details

This helps confirm whether the document is genuine and who issued it.

Why is UDIN important for businesses?

For businesses, UDIN ensures that their compliance documents are accepted without delay.

UDIN helps businesses by:

• Avoiding rejection of CA-certified documents
• Reducing compliance risks
• Ensuring smooth tax and regulatory filings
• Building credibility with authorities

Many income tax and GST filings rely on UDIN-backed certificates.

What happens if UDIN is missing?

If a document that requires UDIN does not have it:

• The document may be treated as invalid
• Authorities may reject the filing
• Re-submission may be required
• Compliance deadlines may be missed

This can lead to unnecessary delays and penalties.

Simple example to understand UDIN

Suppose a company files Form 3CEB for transfer pricing compliance. The form is certified by a Chartered Accountant and includes a UDIN number.

The Income Tax Department can verify the UDIN to confirm:

• The report was issued by a registered CA
• The document is authentic
• The details match ICAI records

Without UDIN, the same form may be questioned.

How Ebizfiling helps ensure UDIN compliance?

At Ebizfiling, we ensure that all CA-certified documents issued to our clients are UDIN compliant. We coordinate closely with Chartered Accountants so that documents are correctly certified and accepted by authorities without issues.

Conclusion

UDIN may look like just another number, but it plays a very important role in today’s compliance system. It protects businesses, Chartered Accountants, and authorities by ensuring that documents are genuine and verifiable.

Understanding what is UDIN and how the UDIN works helps businesses avoid rejections, delays, and compliance problems.

Please go through what people are Frequently Asking about UDIN