“More bad news for UK exporters,” was how the British Chambers of Commerce summed it up. Northern manufacturers, food producers and logistics firms spent the weekend re‑pricing orders to the United States after President Donald Trump said he would lift his new global tariff from 10% to 15%. The 10% surcharge has been formally proclaimed by the White House under Section 122 of the 1974 Trade Act and begins on Tuesday 24 February; the President has since said he intends to push it to the legal ceiling for a temporary period. The BBC, the Financial Times and the Wall Street Journal all reported the step‑up to 15% following Friday’s Supreme Court ruling.

The legal backdrop is stark. On Friday 20 February, the US Supreme Court ruled 6–3 that the President overstepped by using the International Emergency Economic Powers Act to impose sweeping tariffs. Chief Justice John Roberts authored the majority opinion; Justices Neil Gorsuch and Amy Coney Barrett joined the liberals, while Justices Clarence Thomas, Samuel Alito and Brett Kavanaugh dissented. The Brennan Center for Justice notes the decision, Learning Resources v Trump, curbs emergency powers for tariff‑making and kicks refund questions to lower courts.

Within hours of the ruling, the White House issued a proclamation establishing a 10% universal surcharge under Section 122 of the 1974 Act, effective from 24 February for up to 150 days. The administration has since said it will raise the rate to 15%, the statute’s maximum, during that temporary window. Congressional Research Service material and trade analysts have long described Section 122 as a rarely used authority-indeed, never previously invoked for tariffs-designed for short‑term balance‑of‑payments problems.

Crucially for supply chains in the North, the proclamation carves out broad exemptions. The surcharge does not stack on top of existing national‑security tariffs under Section 232, and it excludes categories including pharmaceuticals and ingredients, certain electronics, aerospace products, and-importantly for British industry-passenger vehicles, some trucks and a range of automotive parts. Goods qualifying as Canadian or Mexican under USMCA rules are also excluded, according to the White House text.

That tangle of rules now sits alongside last year’s UK‑US Economic Prosperity Deal. The Department for Business and Trade said the deal created a 10% tariff‑rate quota for UK car exports and removed tariffs on many civil aerospace products, with new quotas expected for steel and aluminium. London insists Britain’s “privileged trading position” with the US should continue, pointing to those sectoral carve‑outs, while acknowledging Washington will determine how Section 122 is applied.

What does this mean north of the Trent? ONS data show the United States was the UK’s largest goods export market in 2024, including £9bn of cars and strong sales in machinery and pharmaceuticals. With vehicles, aerospace and many medicines listed among exemptions, some of the North’s flagship sectors may avoid the surcharge for now. But industrial machinery, processed foods and other manufactured goods that are not exempt could face a 10–15% cost hit on entry to the US from this week.

Manufacturers’ body Make UK previously warned US tariffs were “devastating for UK manufacturing,” highlighting the risk to integrated supply chains that run through Sheffield, Teesside, the Humber and Lancashire. The British Chambers of Commerce has again cautioned that higher US duties are “bad news for UK exporters,” urging ministers to keep negotiating to limit damage. Local chambers across the North West and Yorkshire tell us firms are holding prices where they can, but warning letters to customers are being drafted in case the 15% is signed.

Across the Atlantic, the refund battle has already begun. The US Chamber of Commerce said “swift refunds” of unlawfully collected duties under the struck‑down regime would be meaningful for more than 200,000 small‑business importers. The National Retail Federation urged courts to ensure a “seamless process”. None of this is instant: the Supreme Court left refunds to lower courts, and trade lawyers expect months-if not years-of casework before cheques arrive.

For Northern exporters, who actually gets a refund will hinge on paperwork. If a UK firm sold Delivered Duty Paid and acted as importer of record in the US, it may be in line to claim. If an American distributor was the importer, any rebate would likely flow to them. Trade advisers are telling firms to review Incoterms on all US shipments since last spring, match HS codes against the White House exemption annexes, and speak to customers now about how costs will be shared from 24 February.

The politics will run hot. France’s Emmanuel Macron said fair rules require “reciprocity”. Germany’s chancellor Friedrich Merz warned that “uncertainty” over tariffs is economic “poison”. In Washington, the administration is signalling further moves under Section 301 (unfair trade) and Section 232 (national security) to replace the temporary surcharge once the 150‑day window closes-keeping boardrooms on edge.

The government in London says it is “working with the US” to understand the impact. Officials point to protections already agreed for autos, steel and aerospace, and to ongoing talks on pharmaceuticals. But business groups from the North are blunt: even a short‑lived 10–15% surcharge on non‑exempt goods risks missed orders this spring and squeezes on margins already eroded by energy and wage costs.

For now, the dates to watch are Tuesday 24 February, when the 10% levy starts, and late July, when the Section 122 window closes unless Congress extends it. If the President signs paperwork to take the rate to 15% in the coming days, the squeeze will tighten. Until then, Northern firms will keep recalculating, renegotiating-and waiting for clarity from Washington and Whitehall.