US and Mexico Tighten Customs Rules on Steel and Aluminum to Prevent Tariff Evasion

In a significant regulatory shift aimed at protecting regional trade integrity, the United States and Mexico have implemented strict new customs requirements for steel and aluminum imports. According to reports from Reuters, the joint policy is specifically designed to prevent tariff evasion and block Chinese transshipment through Mexican borders. Under the newly established rules, steel imported from Mexico must be melted and poured within North America—specifically the United States, Mexico, or Canada—to qualify for duty-free status under Section 232 regulations. This joint initiative represents a major step in aligning North American trade enforcement.

In addition to the steel regulations, Bloomberg reports that aluminum imports are now subject to rigorous origin verification. To clear customs, aluminum shipments entering the United States must not contain any primary aluminum smelted in China, Russia, Belarus, or Iran. Importers are now required to provide detailed certificates of analysis to US Customs and Border Protection (CBP) to successfully clear their cargo. This requirement aims to close loopholes that previously allowed non-compliant metals to bypass standard tariffs by routing through third countries.

As noted by the Associated Press, these measures represent a significant tightening of border enforcement and require substantial compliance adjustments from global trade participants. Importers must ensure their documentation is comprehensive and verifiable to avoid costly delays at ports of entry. The policy highlights a growing trend of regional cooperation to enforce trade compliance and protect domestic manufacturing sectors from unfair competition. Businesses operating within the North American supply chain will need to carefully audit their sourcing practices and secure the necessary certificates of analysis to ensure uninterrupted customs clearance.