A bilateral agreement made by two countries to resolve issues involving double taxation of passive and active income. Tax treaties generally determine the amount of tax that a country can apply to a taxpayer's income and wealth. Tax haven countries are the only countries that typically do not enter into tax treaties.

One of the most important aspects of a tax treaty is the policy on withholding taxes, which determines how much tax is levied on income (interest and dividends) from securities owned by a non-resident. For example, if a tax treaty between country A and country B determined that their bilateral withholding tax on dividends is 10%, then country A will tax dividend payments that are going to country B at a rate of 10% and vice versa.