Effective June 4, 2025, the Trump Administration doubled the Section 232 tariffs on the imports of steel and aluminum from 25% to 50% from all countries, except the United Kingdom. The U.K. is exempted from the increased tariffs because of the U.S.-U.K. Economic Prosperity Deal reached on May 8, 2025. These increased tariffs apply to steel and aluminum imports, as well as the steel and aluminum content of certain derivative steel and aluminum products. 

Although the announcement came via social media on May 29, the formal Proclamation was published on the White House website on the evening of June 3. The Proclamation's implementation by Customs was further clarified by several simultaneously published messages. The Proclamation Adjusting U.S. Imports of Aluminum and Steel inverts the stacking order originally created by the April 29, 2025 Executive Order. The new Proclamation and Customs guidance clarifies that Section 232 steel and aluminum tariffs do not stack on top of the IEEPA Fentanyl tariffs as it pertains to Canada and Mexico. 

The Proclamation and Customs message reminds importers that derivative articles of steel and aluminum, which are subject to Section 232 tariffs on the value of their steel and aluminum, will also be subject to reciprocal tariffs on their non-steel and aluminum value.  

Interestingly, both the steel and aluminum Customs guidance messages provide an exemption or 0% tariff for steel or aluminum articles or derivative products that are (a) cast and poured (for steel) or (b) smelt and cast (for aluminum) in the United States.  Mill certifications and other Country of Origin documentation will be critical for the implementation of these tariffs.

Other noteworthy tariff developments: As a development to our prior blog on the Court of International Trade's decision finding that the President's IEEPA tariffs are illegal. On May 29, after the U.S. filed an appeal in the Court of Appeals for the Federal Circuit and motioned for a stay of the remedy, the Federal Circuit temporarily granted the stay.  A similar process will likely occur if and when the U.S. Supreme Court considers the CIT's decision. So the IEEPA tariffs will remain in effect, likely until all appeals are exhausted.