UDIN in Form 145 (Previously 15CA) and Form 146 (Previously 15CB) : What You Need to Know
Learn how UDIN works in Form 145 (Previously 15CA) and Form 146 (Previously 15CB) , why it matters for CA certification, ICAI API verification, and the Form 145 (Previously 15CA) Part C filing process.
When a foreign remittance requires a Chartered Accountant's certificate, one of the important changes under the new Income-tax Rules, 2026 is the introduction of UDIN in Form 146 (Previously 15CB).
UDIN stands for Unique Document Identification Number. It is used to help verify the authenticity of documents certified by Chartered Accountants.
What is UDIN?
UDIN is a unique number generated by a Chartered Accountant for documents certified by them.
Under the new framework, UDIN has been introduced in Forms 145 and 146, with the Income Tax Department stating that it enables real-time verification through the ICAI API.
The objective is straightforward: make it easier to verify that a certificate has actually been issued by the concerned CA.
Where Does UDIN Matter in Form 146?
Form 146 is the accountant's certificate used when the taxpayer is filing Form 145 Part C.
The CA completes the required details in Form 146 and provides the relevant verification information, including UDIN.
This creates an additional verification layer between the CA, taxpayer and Income Tax Department.
Why Was UDIN Introduced?
The main purpose is authenticity and transparency.
Under the earlier system, a CA certificate was an important supporting document for certain foreign remittances. The new framework introduces technology-based verification so that the authenticity of the certificate can be checked electronically.
The Income Tax Department specifically describes the UDIN feature as enabling real-time verification through the ICAI API.
Does Every Form 145 Have a UDIN?
Not necessarily.
The important distinction is between Form 145 and Form 146.
Form 146 is the accountant's certificate. UDIN is particularly relevant to the CA certification process.
If a taxpayer is filing Part B of Form 145 based on an Assessing Officer's certificate/order, there is no requirement to obtain Form 146. Therefore, the taxpayer does not go through the CA certification route merely because the remittance exceeds ₹5 lakh.
Simple Example
An Indian company wants to make a taxable foreign remittance of ₹20 lakh.
If it chooses Part C, it obtains Form 146 from a CA.
The CA completes Form 146 and provides the required UDIN details.
The taxpayer then uses the Form 146 acknowledgement while completing Form 145 Part C.
If instead the taxpayer has an applicable AO certificate/order and uses Part B, Form 146 is not additionally required.
Final Takeaway
UDIN makes the new Form 146 process more technology-driven by allowing verification of the CA certificate.
For businesses, the practical flow is:
CA reviews transaction → Form 146 (Previously 15CB) prepared → UDIN provided → Form 146 (Previously 15CB) submitted → acknowledgement generated → Form 145 Part C filed