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Unique Document Identification Number (UDIN) for Practicing Chartered Accountants

Updated: Dec 15, 2023

UDIN (Unique Document Identification Number): A Complete Guide
UDIN (Unique Document Identification Number): A Complete Guide

The attestation of a Chartered Accountant on a certificate or any such document is of immense value since it usually signifies that the Chartered Accountant, in his professional opinion, has ensured that there is no misrepresentation by the entity issuing/submitting such a document.


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A prime example of this being an audit report issued by the auditor in respect of the financial statements of an entity stating the financial statements reflect a true and fair view of the state of affairs of the entity. It is because of this attestation or signature made by the Chartered Accountant that the investors and other stakeholders can rely on the performance of an entity.

How did UDIN come into play?

To curb the malpractices of certification by non-CAs by impersonating themselves as CAs, the ICAI has come out with an innovative concept of UDIN i.e. Unique Document Identification Number which has been implemented in a phased manner.

It will secure the certificates/reports/ documents attested/certified by practicing CAs. This will also enable the Regulators/Banks/Third parties to check the authenticity of the certificates/reports/documents.

What is a Unique Document Identification Number (UDIN)?

Unique Document Identification Number (UDIN) is an 18-Digits system generated unique number for every document certified/attested by Practicing Chartered Accountants.

The 18- digits UDIN (YY MMMMMM AANNNAANNN) will be like;



First 2 Digits are YY - Last 2 digits of the Current Year (19 in this case)

Next 6 Digits are MMMMMM – ICAI’s Membership No. (304576 in this case)

Next 10 Digits are AANNNAANNN –Alpha-numeric generated randomly by the system (AKTSBN1359).

Applicability of UDIN

Generation of UDIN mandatory for every signature of Full time Practising Chartered Accountants in phased manner for the following services:

  1. All Certificates with effect from 1st February, 2019

  2. GST and Income Tax Audit with effect from 1st April, 2019

  3. All Audit and Assurance Functions with effect from 1st July, 2019

Therefore, UDIN is being made mandatory for all Audit and Assurance Functions like Documents and Reports certified / issued by full time Practising Chartered Accountants from 1st July, 2019

Certificates covered under UDIN

It is mandatory to obtain a Unique Document Identification Number for ALL Certificates issued where the Financial Information/related contents are certified as True and Fair / True and Correct.

Illustrative list of Certificates covered under UDIN:

  • Capital Contribution Certificate/Net Worth Certificate

  • Certificate issued by Statutory Auditors of Banks

  • Certificate Regarding Sources of Income

  • Certification for claim of refund under GST

  • Certification of Fair Values of Shares of Company for Buy Back

  • Certification of Fair Values of Shares of Company for the scope of merger / de-merger

  • Net worth Certificates for Bank finances

  • Net worth Certificates for Bank Guarantee

  • Turnover Certificate

Illustrative list of Certificates not covered under UDIN:

  • Auditor's Opinion/Reports issued by the Practicing Chartered Accountant under any Statute w.r.t. any entity or any person (e.g.: Tax Audit, Transfer Price Audit, VAT Audit, GST Audit, Company Audit, Trust Audit, Society Audit, etc.,

  • Valuation Reports,

  • Quarterly Review Reports,

  • Limited Review Report