Something which may have past you by.
Currently, if a consumer buys an item from Europe the local rate of VAT is charged. After Brexit items sent from the EU to the UK won't be charged VAT (one of the huge issues around the NI border).
The government has pledged that in the event of a no deal the Low Value Consignment Relief (LVCR) will not be extended to these items. This means that every item of value will be held at the post office until you pay the VAT.
The government expects to have a technological solution in place where overseas retailers will register to pay VAT to HMRC.
Clearly this is not going to be in place by March.
As the campaign group Retailers Against Tax Fraud, www.ravas.org.uk will tell you HMRC have a woeful record of letting tax fraud take place.
Given the overwhelming volume of items, it is more than likely HMRC will just waive them through.
The effect on British retaillers is likley to be profound. As is the effect of the unpaid tax.