A decision by President Trump to close a tariff loophole could change the landscape of online shopping, particularly for the Chinese e-commerce companies behind wildly successful sites, such as Shein and Temu.

Americans love Shein, Temu and AliExpress for two reasons: low prices and fast shipping. Trump’s tariffs could change that. His tariff orders reversed a long-standing shipping loophole: the de minimis exemption.

President Donald Trump’s sweeping tariff threats have been touch and go. As it stands currently, the 25 percent tax on goods from Mexico and Canada is on ice for a month, but a 10 percent tariff on Chinese goods is set to take effect on Tuesday, via an executive order of questionable legality.