Tax

===Tariff===
{{Main|Tariff}}
An import or export tariff (also called customs duty or impost) is a charge for the movement of goods through a political border. Tariffs discourage [[trade]], and they may be used by governments to protect domestic industries. A proportion of tariff revenues is often hypothecated to pay the government to maintain a navy or border police. The classic ways of cheating a tariff are [[smuggling]] or declaring a false value of goods. Tax, tariff and trade rules in modern times are usually set together because of their common impact on [[industrial policy]], [[investment policy]], and [[agricultural policy]]. A [[trade bloc]] is a group of allied countries agreeing to minimize or eliminate tariffs against trade with each other, and possibly to impose protective tariffs on imports from outside the bloc. A [[customs union]] has a [[common external tariff]], and the participating countries share the revenues from tariffs on goods entering the customs union.

In some societies, tariffs also could be imposed by local authorities on the movement of goods between regions (or via specific internal gateways). A notable example is the ''[[likin (taxation)|likin]]'', which became an important revenue source for local governments in the late [[Qing Empire|Qing China]].