The full form of TAN NO is Tax Deduction and Collection Account Number.

Tax Deduction Account Number or Tax Collection Account Number is a 10 -digit alpha-numeric number issued by the Income-tax Department. TAN is to be obtained by all persons who are responsible for deducting tax at source (TDS) or who are required to collect tax at source (TCS).

How to apply for TAN?

There are two modes for applying for TAN:

• OFFLINE – An application for allotment of TAN is to be filed in Form 49B in duplicate and submitted to any TIN-FC. Addresses of TIN FCs are available at NSDL TIN website (https://www.tin-nsdl.com).
• ONLINE — Online application for TAN can be made from the website of NSDL TIN website.

Tax Deduction Account Number or Tax Collection Account Number is a 10-digit alphanumeric number issued by the Income-tax Department (we will refer to it as TAN). TAN
is to be obtained by all persons who are responsible for deducting tax at source (TDS) or
who are required to collect tax at source (TCS).
Structure of TAN
First 4 digits of TAN are alphabets, the next 5 digits of TAN are numeric and last digit is
an alphabet.
First 3 alphabets of TAN represent the jurisdiction code, 4th alphabet is the initial of the
name of the TAN holder who can be a company, firm, individual, etc. For example, TAN
allotted to Mr. Mahesh of Delhi may appear as under:
DEL M 12345 L