The negotiation of this protocol followed the failure of the Irish “backstop” system to obtain the approval of the British Parliament. The Protocol on Northern Ireland aims to prevent there from being an EU external border between Ireland and Northern Ireland, which would lead to a “hard border” on the island of Ireland and aims to allow goods to cross the island of Ireland as it is currently practiced without customs controls. The protocol obliges the United Kingdom to comply with the European Commission`s decisions on trade in Northern Ireland. In accordance with the Protocol, all necessary customs controls are carried out when goods pass between Northern Ireland and the rest of the United Kingdom. The Single Market Act aims to make trade regulations compatible in England, Scotland, Wales and Northern Ireland.