STT is a kind of financial transaction tax which is similar to tax collected at source (TCS). STT is a direct tax levied on every purchase and sale of securities that are listed on the recognized stock exchanges in India. STT is governed by Securities Transaction Tax Act (STT Act) and STT Act has specifically listed down various taxable securities transaction i.e., transaction on which STT is leviable.

Taxable securities include equity, derivatives, unit of equity oriented mutual fund. It also includes unlisted shares sold under an offer for sale to the public included in IPO and where such shares are subsequently listed in stock exchanges. STT is an amount to be paid over and above transaction value and hence, increases transaction value.