U.S. Customs and Border Protection (CBP) recently issued guidance via the Cargo Systems Messaging Service (CSMS) on filing entries for imports from Canada subject to duties under Section 338 of the Tariff Act of 1930 (Section 338). We previously covered President Trump’s imposition and subsequent modification of these Section 338 tariffs here, here, and here.
On September 8, 2026, President Trump issued five Proclamations that banned imports of certain products from Canada and modified the scope of products subject to 50% tariffs under Section 338 of the Tariff Act of 1930 (Section 338) including subjecting new products to the tariffs.
In the latest development in United States-Canada trade relations, 50% additional duties, announced in three separate proclamations issued on July 20, 2026, took effect as of 12:01 a.m. eastern time on August 22, 2026. President Donald Trump imposed the additional duties pursuant to Section 338 of the Tariff Act of 1930, which empowers the President to impose additional duties (not exceeding 50%) on imports from a foreign country to offset the burden or disadvantage caused by that country’s unequal imposition on or discrimination against U.S. commerce.
President Donald Trump issued a proclamation on August 18, 2026, pushing back the effective date of 50% Section 338 tariffs on certain Canadian goods by three days, to 12:01 a.m. Eastern on August 22, 2026. The delay was announced just hours before the new Section 338 tariffs were to go into effect on August 19