It is important to emphasise that these changes are only expected to happen if there is no deal, which the government describes as ‘unlikely’.
Some changes are expected to the way VAT is accounted for on the trade in goods and services between the UK and the EU.
The no deal guidance highlights the unique position of Northern Ireland, which could have the UK's only land border with the EU.
The government has repeatedly said that there will not be a physical border between Northern Ireland and Ireland, but the guidance lacks any detail as to how trade arrangements will operate.
It notes that the Irish government will need to consult with the EU in the event of no deal, and recommends that businesses consult with the Irish government for guidance on the preparations needed.
The no deal guidance also details some changes which may not have a widespread impact, but nonetheless would be significant for those to whom they apply.