UDIN (Unique Document Identification Number) is mandatory for every attestation, certification, and audit report a Chartered Accountant signs. Firms managing high volumes of certificates face the challenge of tracking UDIN generation status across multiple professionals, across dozens of document types. This guide covers the complete UDIN workflow and how to manage it at scale.
What Is UDIN and Why It Matters
UDIN is a unique number generated on the ICAI UDIN portal (udin.icai.org) by the CA who signs or certifies a document. It allows anyone—banks, regulators, courts, counterparties—to verify the authenticity of a CA-certified document online using only the UDIN number and the document type.
UDIN was made mandatory in phases: first for bank-submitted certificates (2019), then for audit reports (2020), and then for all certification documents (2021). As of 2026, every professional attestation or certification by a CA requires a UDIN within the time limits set by ICAI.
Documents That Require UDIN
| Document Type | UDIN Required | Time Limit |
|---|---|---|
| Statutory audit report (Form 3CA/3CB + 3CD) | Yes | 60 days from signing |
| Tax audit report | Yes | 60 days from signing |
| Net Worth Certificate | Yes | 60 days from signing |
| Bank certificate / credit facility certificate | Yes | 15 days from signing |
| Form 15CA/15CB (FEMA remittance certificate) | Yes | 15 days from signing |
| Project completion certificate | Yes | 60 days from signing |
| GST reconciliation statement signed by CA | Yes | 60 days from signing |
| GSTR-9C (signed by CA) | Yes | Same day as filing |
| Turnover certificate for tender | Yes | 15 days from signing |
| Stock / debtors / creditors certificate for bank | Yes | 15 days from signing |
Note: Time limits are counted from the date the CA signs the document, not the date it is submitted to the requesting party. Always check the ICAI UDIN portal for the latest list of mandatory document types.
How to Generate a UDIN (Step-by-Step)
- Log in to udin.icai.org with your ICAI membership number and password.
- Select "Generate UDIN"
- Choose the financial year and document type from the dropdown
- Enter the client's GSTIN/PAN (as applicable) and the document date
- Enter the financial figure (as applicable — the exact turnover/net worth the certificate attests)
- Submit — a 18-character UDIN is generated immediately
- Note the UDIN on the signed document (in the signature block or certificate text)
UDIN Revocation: When and How
A UDIN must be revoked when the original document it was generated for is modified, cancelled, or superseded. Common revocation scenarios:
- A bank certificate is reissued with a corrected amount
- An audit report is revised after the original was signed
- A net worth certificate was signed in error and needs to be cancelled
Revocation must happen within 60 days of the original generation. After revocation, a new UDIN must be generated for the revised document if it is still being used.
Managing UDIN at Scale: A System for CA Firms
A firm with 5+ CA professionals generating 50–100 UDINs per month needs a tracking system. Without it, you will:
- Miss the 15-day window for bank certificates
- Forget to revoke UDINs for revised documents
- Have no audit trail when a bank asks "which CA signed this and when?"
Minimum UDIN Tracking Fields per Certificate
| Field | Why Track It |
|---|---|
| Client name + PAN/GSTIN | Link to the right client record |
| Document type | Determine UDIN time limit (15 or 60 days) |
| Date signed | Calculate UDIN deadline |
| UDIN generated (Y/N) | Identify outstanding UDINs |
| UDIN number | For verification and audit trail |
| CA member who signed | Only that CA can generate the UDIN |
| Revocation status | Track if document was revised |
TaxZeo tracks UDIN generation status for every signed document across all professionals in your firm — with deadline alerts before the 15-day and 60-day limits expire.
Start Free TrialFrequently Asked Questions
Can a junior staff member generate UDIN on behalf of the CA?
No. UDIN must be generated by the CA whose membership number will be associated with the document — only that CA's login on udin.icai.org can generate the UDIN. While staff can prepare the details (document type, financial figures, client PAN), the final generation step must be done by the CA personally. Sharing ICAI portal credentials with staff is a violation of ICAI norms.
What happens if a UDIN is not generated within the time limit?
The ICAI can flag the CA for disciplinary action for non-compliance with UDIN requirements. In practical terms, the bank or counterparty may reject the certificate when they try to verify it and find no UDIN. The CA will need to revoke the old certificate, regenerate it with a UDIN, and resubmit — causing delay and potential damage to the client relationship. ICAI has periodically run compliance drives checking for certificates without UDINs, particularly for bank certificates.