TAN
Tax deduction and collection account number: the number a business needs before it deducts TDS.
A TAN is separate from your PAN. Anyone required to deduct or collect tax at source needs one, and it goes on every TDS payment and return.
A small business that never deducts TDS does not need one. The day you start paying rent, contractors or staff in a way that requires deduction, you do.
Learn it in a lesson
See also: TDS