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,

The trade loophole is meant to ease small-scale sales — but critics say it's been abused and gives Chinese firms an unfair advantage.

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

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