Tariff uncertainty for planners

Tariff planning got harder after a UK Parliament briefing said the Trump administration is using import taxes as leverage — and the legal basis for some of them changed on February 20, 2026. (commonslibrary.parliament.uk) The House of Commons Library briefing, published April 14, 2026, says a 10% tariff still applies to most UK goods entering the United States, while steel, aluminium and derivative goods have faced a 25% rate. It says those tariffs, and other countries’ responses, have made the outlook for world trade “much more uncertain.” (commonslibrary.parliament.uk) The Trump administration set out that rationale in a February 13, 2025 fact sheet and an April 2, 2025 emergency order. The White House said the United States had run a goods trade deficit every year since 1975, that the 2024 goods deficit exceeded $1 trillion, and that a 10% baseline tariff would start on April 5, 2025, with higher country-specific rates from April 9, 2025. (whitehouse.gov, whitehouse.gov) The administration’s case is that U.S. markets are more open than many foreign ones. In the February 2025 plan, the White House pointed to Brazil’s 18% tariff on U.S. ethanol versus a 2.5% U.S. tariff, India’s 39% average applied tariff on agricultural goods versus 5% in the United States, and the European Union’s 10% tariff on imported cars versus 2.5% in the United States. (whitehouse.gov) That matters for planners because tariffs are taxes paid by the importing business, not the foreign seller, and they move landed cost before a product reaches a shelf or a checkout page. The Commons Library briefing says the UK-US Economic Prosperity Deal announced on May 8, 2025 only partially implemented relief, with terms that can still evolve by sector. (commonslibrary.parliament.uk) For marketers and procurement teams, that leaves three variables moving at once: input cost, supplier mix and final price. The same Commons briefing says the UK can export up to 100,000 passenger vehicles to the U.S. at a 10% tariff, while pharmaceuticals can enter tariff-free and steel and aluminium relief depends on U.S. supply-chain security requirements. (commonslibrary.parliament.uk) The legal footing shifted again on February 20, 2026, when the U.S. Supreme Court ruled in *Learning Resources, Inc. v. Trump* that the International Emergency Economic Powers Act does not authorize the president to impose tariffs. The Commons Library says that decision removed the legal basis for the reciprocal tariffs and several other measures. (supremecourt.gov, commonslibrary.parliament.uk) The administration did not drop the broader policy after that ruling. On the same day, February 20, 2026, the White House said Trump was switching to section 122 of the Trade Act of 1974 to impose a temporary import duty tied to “fundamental international payment problems,” and U.S. Trade Representative Jamieson Greer said alternative tools would be used if the court limited the earlier tariff authority. (whitehouse.gov, ustr.gov) The White House and the Office of the U.S. Trade Representative have framed the campaign as a way to force lower barriers abroad and win bilateral deals. USTR’s tariff actions page lists agreements or frameworks with the United Kingdom, Indonesia, the European Union, Japan and Malaysia after the April 2025 tariff rollout. (ustr.gov) That leaves planners working off a trade policy that now depends on negotiations, court rulings and substitute legal authorities as much as published tariff tables. The Commons Library’s bottom line is narrower but concrete: even after the UK deal, a 10% tariff remains on most UK goods, and the framework can still change. (commonslibrary.parliament.uk)