The tax placed on legal documents usually in the transfer of assets or property. This duty is customary in the Commonwealth of Nation countries including Singapore and Australia and certain states in the United States. Where enforced, this tax is placed on the transfer of homes, buildings, copyrights, land, patents and securities. The transfer of documents in locations where this law exists, is only legally enforceable once they are stamped, which shows the amount of tax paid. Also referred to as stamp tax.