President Donald Trump’s new global tariffs started taking effect on February 24 at 10%, despite Trump declaring a higher rate of 15%.

The Trump administration is applying the new duties under section 122 of the Trade Act of 1974, which requires approval from Congress only after 150 days. The 10% rate is on top of the U.S.’s most favored nation duties, and was announced by Trump on February 20, after the U.S. Supreme Court struck down the tariffs he implemented under the International Emergency Economic Powers Act (IEEPA). The Guardian reports that the uplift to 15%, announced by Trump one day later on Truth Social, has yet to be implemented, but could be introduced at any time.

According to a notice from the U.S. customs agency, “an additional 10% ad valorem duty on imported articles of every country” has been imposed for a period of 150 days from February 24, unless specifically exempt. Tariffs imposed under Section 122 must not discriminate among countries – meaning Trump can’t threaten different rates applied to different countries in pursuit of bilateral deals.

Reacting to the new 10% U.S. tariff being introduced instead of the expected 15%, William Bain, Head of Trade Policy at the British Chambers of Commerce in London, said the situation shows how difficult it is for businesses to plan ahead.  

“It is far from clear what will happen next, and whether a higher tariff rate is still on the way. Despite the immediate reprieve, there is fresh uncertainty for U.K. firms exporting goods to the U.S.,” said Bain. “This makes it very difficult for firms to understand the prices and margins they will be able to secure for their goods, currently under production, for export in several months’ time. Inevitably this will have an impact on their sales and hit the economy.” 

The BCC has provided government with a six-point plan to guard against the worst economic outcomes from the new tariffs and potential further hikes, which includes continued negotiation with the U.S. government, engagement with the U.S. Congress, an uplift in U.K. Export Finance capacity and reviewing the U.K.’s Global Tariffs. 

“The risk of further tariff pain to come is still real and the government must do everything it can to prepare for the worst,” Bain warned. 

The new 10% tariffs expire on July 24 unless renewed by an Act of Congress.