1, The full form of TAN is Tangent. It’s used on Academic & Science ,Mathematics in Worldwide

Tangent (Tan) is a trigonometric function of an acute angle in a right triangle that is the ratio of the length of the side opposite the angle to the length of the side adjacent to the angle.

In geometry, the tangent is a line that touches the edge of a curve or circle at one point.

2, The full form of TAN is Total Acid Number. It’s used on Academic & Science ,Chemistry in Worldwide

Total Acid Number (TAN) is a measure of acid concentration determined by the amount of potassium hydroxide in milligrams that are needed to neutralize the acids in one gram of oil. It is a quality measurement in a petrochemical sample.

3, The full form of TAN is Tax Account Number. It’s used on Governmental ,Rules & Regulations in India

Tax Account Number (TAN) or Tax Deduction and Collection Account Number, is a 10-digit alphanumeric number issued by the Income Tax Department to individuals who are required to deduct tax at source or collect tax at source. TAN is required to be obtained by individuals who are responsible for Tax Deduction at Source (TDS) or Tax Collection at Source (TCS) on behalf of the Government under the Indian Income Tax Act, 1961.

4, The full form of TAN is Transaction Authentication Number. It’s used on Business ,Banking in Worldwide

Transaction Authentication Number (TAN) is a form of one-time-password which is used by some online banking services to authorize a financial transaction.