A Latin term that’s been little-known outside the world of customs brokers has suddenly become the stuff of headlines. Along with imposing new 10% tariffs on all Chinese imports as of Feb. 4, US President Donald Trump suspended his country’s special rules for “de minimis” merchandise from China and Hong Kong.

Here’s how to understand de minimis and how it turbocharged bargain platforms Shein and Temu.

U.S. President Donald Trump this week shut a trade loophole that has been used to ship low-value packages duty-free from China, the "de minimis" exemption on import tariffs. Trump's halt to Section 321 de minimis is part of his implementation of an additional 10% tariff on China and 25% tariffs on Canada and Mexico,

This chart shows countries applying a "de minimis" exception of taxes and/or duties* for incoming shipments of smaller value.