SDRT, an acronym for Securities Duty Reserve Tax, is a tax chargeable on transactions related to securities, including stocks, shares, and debt instruments, exceeding a specific amount. Synonyms for SDRT include Stamp Duty Reserve Tax, Transfer Tax, Stock Transfer Tax, and Securities Transaction Tax. While the term SDRT is primarily used in the UK, it is often referred to as different names in other countries. For example, India has its version of SDRT called Securities Transaction Tax (STT), and the US has a similar tax system known as Securities Exchange Tax. In summary, the term SDRT is specific to the UK, and other countries have their versions of the tax with different names.