What is Stamp Duty? Stamp Duty is a tax levied on documents which record transactions, such as disposition or transfer of interest from one party to another. Therefore, stamp duty is payable by the person who purchases both residential and non-residential properties in Singapore. How Much Stamp Duty? Sales Stamp Duty Payable = First S$180,000 of purchase price x 1% + Next S$180,000 of purchase price...