British businesses trading on Amazon have been advised to prepare for a no-deal Brexit to ensure they can continue selling to customers in the EU.
The online retail giant has informed sellers that the government said that the "free circulation of goods" between the UK and EU would stop in the event of a no-deal withdrawal.
The UK is scheduled to leave the EU on 29 March, with or without a deal.
Amazon said sellers should consider sending stock to European warehouses.
Currently, stock stored in Amazon's UK warehouses can be delivered to anywhere in Europe.
To plan for no deal, Amazon has told sellers to "be prepared that any units in a UK fulfilment centre might not be fulfilled cross-border to EU customers."
In an email to UK-based sellers sent earlier this month, they said retailers should "consider sending inventory to an EU fulfilment centre by March 17."
Retailers should maintain "the standard recommended minimum of four weeks of inventory coverage at all times," Amazon said.
It is understood there are tens of thousands of UK-based companies selling on Amazon, keen to use the platform to tap into a European and global market.
Joe W. Doherty, manages Marble Hill Natural Skincare, a company based in Derry, Northern Ireland, a city that will straddle the EU-UK border when Britain exits the European Union.
"We sell a lot of our products throughout Europe via Amazon and we've been making contingencies in recent months to ensure demand can be met, at least in the short term, in the event of a hard Brexit," he said.
They have taken Amazon's no deal advice but at a cost to the business.
"We have been loading our products into Amazon's pan-European warehouse to help ensure supply is available for distribution to the European markets," he said.
"Production has been increased and that is having an obvious effect on our business because the products are not being sold immediately."
He added: "There is only so much contingency planning businesses can afford in the face of so many different outcomes."
Amazon told the BBC the guidance was designed to ensure sellers plan and prepare for all scenarios, including the risk of border disruption.
The company said it also included a copy of the UK government's partnership pack in the communication to UK seller, advising how firms should prepare for a no-deal scenarios.
In 2017, UK sellers exported around £2.3bn of goods via Amazon globally.