Donald Trump has cancelled a loophole from today that had allowed consumers and businesses to be spared duties for sending low-value goods to the United States.
The so-called de minimis exemption had applied across the world before Trump 2.0 but the president has taken action - and the UK may soon follow suit - as part of his trade war.
The relief had allowed goods worth less than $800 (£595) to enter the US duty-free since 2016 - and for decades before that at a lower threshold.
But now, low-cost packages face the same tariff rate as other, more expensive, goods.
The reasons for the latest bout of protectionism are numerous and the ramifications are country and purpose specific.
What is changing?
It was no accident that China was the first destination to be slapped with this rule change.
The duty exemption on low-value Chinese goods was ended in May as US retailers, in fact those across the Western world, complained bitterly that they were being undercut by cheap clothing, accessories and household goods shipped by the likes of Shein and Temu.
From today, Mr Trump is expanding the end of the de minimis rule to the rest of the world.
Why is Trump doing this?
The president is not acting purely to protect US businesses.
More duties mean more money for his tariff treasure chest, bolstering the goodies already pouring in from his base and reciprocal tariffs imposed on trading partners globally this year.
The Trump administration has also called out "deceptive shipping practices, illegal material and duty circumvention".
It also believes many parcels claiming to contain low-value goods have been used to fuel the country's supplies of fentanyl, with the importation of the illegal drug being used by the president as a reason for his wider trade war against allies including Canada.
How will it apply?
Under the new rules, only letters and personal gifts worth less than $100 (£74) will still be free of import duties.
Charges will depend on the tariff regime facing the country from where the goods are sent.
Fox example, a parcel containing products worth $600 would raise $180 in extra duties when sent from a country facing a 30% tariff rate.
It has sparked chaos in many countries, with postal services in places including Japan, Germany and Australia refusing to accept many items for delivery to the US until the practicalities of the new regime become clearer.
What about the UK?
All goods not meeting the £74 exemption criteria now face a 10% charge because that is the baseline tariff the US has slapped on imports from the UK.
We were spared, if you remember, higher reciprocal tariffs under the so-called "trade deal".
How will the process work?
All shipping and delivery companies will be wading through the changes, with the big international operators such as DHL, FedEx and the like all promising to navigate the challenge.
Royal Mail said on Thursday that it would be the first international postal service to have a dedicated operation.
It said consumers could use its new postal delivery duties paid (PDDP) services both online and at Post Offices.
But it explained that business customers faced different restrictions to individuals.
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Businesses would be charged a handling fee per parcel to cover additional costs and duties would be calculated based on where items were originally manufactured.
While business account customers could be handed an invoice for the duties, it explained that consumers would have to pay at the point of buying postage.
No customs declaration would be required, it concluded, for personal correspondence.
Is the US alone in doing this?
The answer is no, but it remains a fairly widespread relief globally.
The European Union, for example, removed de minimis breaks back in 2021, making all e-commerce imports to the bloc subject to VAT.
It is also now planning to introduce a fee of €2 on goods worth €150 or less to cover the costs of customs processing.
Should the UK do the same?
The UK has been under pressure for many years to follow suit and drop its own £135 duty-free threshold as retailers battle the cheap e-commerce competition from China we mentioned earlier.
A review was announced by the chancellor in April.
Sky News revealed in July how the total declared trade value of de minimis imports into the UK in the 2024-25 financial year was £5.9bn - a 53% increase on the previous 12-month period.
Any rise in revenue would be welcomed, not only by UK retailers, but by Rachel Reeves too as she looks to fill a renewed black hole in the public finances.
(c) Sky News 2025: How the US trade war is now targeting you from today