A new executive order restored a provision that allows low-value shipments to avoid taxes and tariffs.

Logistics firms are scrambling to adjust to President Donald Trump’s new rules that threaten to upend their booming business delivering small parcels from Chinese sellers to American buyers.

Ending tariff exemptions on low-cost packages from China has broad bipartisan support in Washington, and Trump pulled the plug when he raised tariffs on Chinese goods by 10% earlier this week. Goods sent through duty-free packages became subject not only to existing tariffs — 25% for many Chinese products — but also the new 10%.