when do tariffs go into effect

The most recent tariffs introduced by President Trump had varying effective dates. A set of new tariff rates were initially expected to take effect on August 1, 2025, but most were delayed until August 7, 2025, to allow Customs and Border Protection time to adjust. Notable exceptions included Canada's tariffs, which started on August 1. Additionally, the United States and the European Union agreed on a written trade framework, and some expanded list tariffs took effect on August 18, 2025. Other tariffs, like the "universal" 10% baseline tariff took effect on April 5, 2025, and reciprocal tariffs on specific countries commenced on April 9, 2025. Certain tariffs—such as those involving China—have had complex timelines involving suspensions and extensions, with some tariffs continuing to be adjusted through negotiation periods in 2025. In summary, for many countries, the latest tariffs went into effect predominantly on August 7, 2025, with some variations by country and tariff type.