Japan and Switzerland’s postal systems have recently halted deliveries to the U.S., coinciding with the impending termination of a tax exemption for imports.

Since 2016, the “de minimis” rule allowed items valued under $800 to enter duty-free. This exemption is now set to end on Friday, following an executive order from President Donald Trump last month.

This adjustment has unsettled small enterprises and shoppers, who are now worried about potential shipping delays and increased expenses. Some business operators have even mentioned on social media that they might have to shut down.

“The ambiguity surrounding tariff collection is significant,” stated Caleb Silver, Investopedia’s editor-in-chief. “Questions remain about who will administer these tariffs and if any items might be exempt, adding further complexity to an already bewildering tariff landscape affecting the U.S.”

From Friday onwards, incoming international goods will face country-specific tariffs. For example, an item worth $800 from nations like China, Brazil, or Canada, with a 25% tariff, could incur an additional cost of at least $200 to import into the U.S.

Under the new rules, letters and personal gifts worth less than $100 will still be duty-free.

The White House asserts that removing the de minimis exemption aims to tackle misleading shipping methods, illegal imports, and tariff evasion. It accused some carriers of exploiting the rule to send drugs like fentanyl into the country.

The de minimis exemption had also been a focal point of the administration’s trade spat with China. Chinese-linked e-commerce companies like Temu and Shein surged in popularity among American consumers by directly shipping cheap clothes and goods under the de minimis threshold. Despite the ongoing conversation between the U.S. and China on a framework trade agreement, the administration ended the de minimis exemption for low-value imports from China and Hong Kong in early May, prompting Temu and Shein to switch to a “local fulfillment model” to avoid price hikes.

On Monday, Swiss Post and Japan Post announced they would soon suspend shipments bound for the United States. Postal services in Australia, India, New Zealand, the U.K. and other parts of Europe have said they will also stop shipping parcels to the States this week.

DHL, one of the biggest delivery companies in the world, said Friday it will stop accepting parcels destined for the U.S. starting Monday, saying that “key questions remain unresolved, particularly regarding how and by whom customs duties will be collected in the future, what additional data will be required, and how the data transmission to the U.S. Customs and Border Protection will be carried out.”

Many European postal services say they are pausing shipments now because they cannot guarantee the goods will enter the United States before Friday.

Other delivery services said they would try to pick up the slack. “Our priority is supporting our customers and helping them navigate through the changes going into effect for U.S.-bound shipments on Aug. 29,” FedEx said.