# Mercosur – Common External Tariff (CET) and Exceptions

*Last updated: 2026-06-18*

> The Mercosur Common External Tariff — known by its Spanish acronym CET or AEC (Arancel Externo Común) — is the unified duty rate that Argentina, Brazil, Paraguay, and Uruguay apply to imports from third countries.

The Mercosur Common External Tariff — known by its Spanish acronym CET or AEC (Arancel Externo Común) — is the unified duty rate that Argentina, Brazil, Paraguay, and Uruguay apply to imports from third countries. It forms the foundation of the customs union: goods arriving from outside the bloc pay the same tariff regardless of which Mercosur port of entry they pass through. In practice, the picture is more nuanced: the system provides for both permanent and temporary exceptions covering sensitive sectors such as automotive, textiles, and industries of strategic importance to individual member states. These derogations are administered by Mercosur's governing bodies and reviewed periodically. For importers and customs brokers, identifying the applicable exception in the destination country before calculating the dutiable value is essential.

**Source:** [https://www.mercosur.int/](https://www.mercosur.int/)

## Quick Facts

| Property | Value |
|---|---|
| Term | Mercosur – Common External Tariff (CET) and Exceptions |
| Language | EN |
| Word count | 126 |
| Last updated | 2026-06-18 |
| Source | https://www.mercosur.int/ |

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