When the United Kingdom leaves the European Union, the status of its land border with the Republic of Ireland will inevitably change. The steady growth of trade and networks across this contested border over the past two decades have been largely attributable to their common EU membership and the peace process they have supported in Northern Ireland. Even aside from political sensitivities, any disruption to this integration will have an economic effect that Northern Ireland and the Irish border region can ill afford. As such, the European Council, European Commission and the UK government have repeatedly expressed a desire to avoid the return of a ‘hard border’ across the island of Ireland. Yet the practicalities of retaining such an open border after Brexit are highly complex, particularly if it becomes a customs border once again.