Which WTO principle requires imported and domestic products to be treated alike after entry?

National treatment is the WTO principle requiring imported and domestic products to be treated alike after imported goods enter the market.

The principle prevents a member from using internal taxes or regulations to discriminate against imported products once they have cleared customs. For goods, the rule is set out principally in Article III of the General Agreement on Tariffs and Trade 1994. Similar national-treatment obligations also appear in the WTO agreements on services and intellectual property.

National treatment is different from most-favoured-nation treatment. Most-favoured-nation treatment concerns equal treatment among foreign trading partners, while national treatment compares foreign products or services with domestic ones.

The obligation does not mean every product must receive identical treatment in every circumstance. Legal analysis considers whether the products are comparable and whether a measure changes competitive conditions to the disadvantage of imports. That context is why the principle is more precise than the phrase “treat everyone the same.”