Non-tariff barriers to trade are restrictions to imports but are not in the usual form of a tariff.

They are criticized as a means to evade free trade rules such as those of the WTO, the EU or NAFTA that restrict tariffs. Most common examples are antidumping and countervailing duties, which, although they are called "non-tariff" barriers, have the effect of tariffs but are only imposed under certain conditions. Their use has risen sharply after the WTO rules led to a very significant reduction in tariff use.

Non-tariff barriers may also be in the form of manufacturing or production requirements of goods, such as how an animal is caught or a plant is grown, with an import ban imposed on products that don't meet the requirements. Examples are the European Union restrictions on genetically modified organisms or beef treated with growth hormones.

Non-tariff trade barriers are expressly permitted in very limited circumstances, when they are deemed necessary to protect health, safety, or sanitation, or to protect depletable natural resources.

Non-tariff barriers to trade can be:

• State subsidies, procurement, trading, ownership
• National regulations on health, safety, employment
• Product classification
• Quotas
• Foreign Exchange: controls and multiplicity
• Over elaborate or inadequate infrastructure
• 'Buy national' policy