The changes mean packages valued at under $800 will face the same tariff rate as other goods from their country of origin – for the UK that’s 10%.

Previously, the de minimis exemption meant goods valued at $800 or less could enter the US without paying any border taxes.

The exemption was criticised by the president and his predecessor, Joe Biden, as harmful to US businesses as it allowed cheap goods from abroad to be quickly shipped from the manufacturing source – with no warehouse stock or associated overhead costs.

US consumers used the exemption to buy cheap clothes and household items from online commerce sites like Shein and Temu, as well as from countries other than China.

But from Friday, “a typical $100 order could now incur an additional $30 to $50 in costs, depending on the final sales tax rate adopted by US authorities,” says Martin Hamilton, partner and head of retail at accountancy firm Menzies.

“On top of that, brands will face extra fees from shipping providers for handling duties and taxes,” he says.

Julian Boaitey started his African skincare brand Yendy Skin in 2021 and said the US market had grown for his company with 20% of sales coming from across the Atlantic.

He had planned to make the American market 80% of his business but says he is now exploring whether to manufacture a small range in the US or export larger volumes there and ship directly to consumers from the US.

“The most frustrating thing is we don’t know what to do,” he says.

“I think we’re all trying to figure out exactly what we’re going to do and how we’re going to go about it.”

Earlier this month, postal services around the world paused some deliveries to the US over confusion around the new rules.

The Royal Mail says it has been working with the US authorities and international partners so its services will meet the new US de minimis requirements when they come into effect on Friday.