UDIN

UDIN stands for Unique Document Identification Number. It is a number generated from the ICAI UDIN portal that authenticates documents certified or attested by a practising Chartered Accountant. The system was introduced by ICAI to curb forged certificates issued in the name of CAs.

Why it matters

When a CA signs a certificate, audit report or attestation, a UDIN is generated against that document on the ICAI portal. Any third party — a bank, a regulator, a client — can then verify the UDIN online to confirm the document is genuine and was issued by that specific member.

In practice this means:

• Each certified document gets its own UDIN
• The CA records key details of the document when generating it
• Regulators increasingly require the UDIN to be quoted on filings

For audit work, UDIN generation is a standard step. A tax audit report, for instance, must carry a valid UDIN. It sits alongside the DSC the CA uses to actually sign filings on the portals.

For a firm, the practical challenge is making sure every certifiable document has its UDIN generated, recorded and not missed during busy filing periods. Some practice management software helps log UDINs against client work so nothing is overlooked.

See how tools handle certification tracking in our rankings and our QwikCA review, and explore related audit terms in the glossary.