How do customs unions facilitate cross-border trade, and which is a well-known example?

• A. They coordinate only border procedures without tariffs
• B. They eliminate internal tariffs and adopt a common external tariff; example: European Union Customs Union
• C. They maintain separate external tariffs but align some internal rules
• D. They allow each member to set its own external tariff independently

Answer: (B)

A customs union works by removing tariffs among member countries and adopting a single, common external tariff for goods imported from outside the union. This setup makes trade within the group seamless and predictable, since there are no border taxes between members and traders don’t have to navigate different tariff rates in each country. At the same time, a common external tariff prevents markets from undercutting each other and creates a level playing field, because imports from outside the union face the same duty regardless of which member they enter. To keep trade fair and prevent tariff avoidance, customs unions also often require rules of origin to ensure that goods genuinely come from within the union before enjoying tariff-free access.

A well-known example is the European Union Customs Union, which embodies this approach with free movement of goods inside the union and a common external tariff on imports from outside.

The other descriptions don’t fit a customs union: merely coordinating border procedures without tariffs would not address external duties; maintaining separate external tariffs while aligning internal rules resembles a looser arrangement like a free trade area with some harmonization; and letting each member set its own external tariff independently would defeat the purpose of unified external policy and tariff coherence.