02 August 2025
The **Unique Document Identification Number (UDIN)** introduced by ICAI is a system to authenticate and track documents certified or signed by practicing Chartered Accountants. Here's a quick overview and how it works:
### What is UDIN?
* UDIN is a unique number generated by the ICAI portal for each document certified or signed by a CA. * It helps in verifying the authenticity of certificates, reports, or any other documents issued by CAs.
### Procedure to use UDIN:
1. **Register/Log in on UDIN portal:** Visit [UDIN portal](https://udin.icai.org/) and log in using your ICAI membership details.
2. **Generate UDIN for each document:** For every certificate or document you sign, you must generate a UDIN by entering the required details (e.g., type of document, client name, date, etc.).
3. **Mention UDIN on the document:** The generated UDIN should be mentioned on the document, usually near the signature or certification section, along with the date and your membership number.
4. **Verification:** Anyone (clients, regulators, etc.) can verify the UDIN on the ICAI portal by entering the UDIN number to confirm the document’s authenticity.
### Is it mandatory?
* ICAI has made UDIN mandatory for various certificates and reports signed by CAs to curb fraudulent certifications. * It’s best practice to generate and mention UDIN on all professional documents to maintain compliance.
### What about check digit?
* The UDIN itself is generated with an internal algorithm and includes a check digit or validation mechanism as per ICAI's system. You don’t need to add any extra check digit yourself.
### How to trace document validity?
* Anyone can go to the UDIN portal, input the UDIN number mentioned on the document, and verify the document’s details and authenticity online.
---
If the ICAI website or portal feels unclear, you can also contact ICAI support or your regional ICAI office for detailed guidance and latest updates on UDIN use.
Would you like a step-by-step guide on generating UDIN from the portal?