Since the UK 2016 referendum, the border between Ireland and Northern Ireland has emerged as the most contested issue affecting the UK’s withdrawal from the European Union. The ‘backstop’ has consistently been the primary reason for the rejection by the House of Commons of the withdrawal deal negotiated between the EU and the UK government. The associated discourses on finding a border ‘solution’ have raised more questions than answers, with many contributors speculating on what might or might not work, rather than presenting any concrete or workable alternatives to the ‘backstop’. The wider debate on how to reconcile the UK’s withdrawal with maintaining an open border on the island of Ireland, in line with the EU’s fundamental freedoms, has highlighted the distinct differences, in several respects, between internal and external EU borders. Internal EU borders are frictionless and largely invisible, and their significance has declined, due to ongoing processes of European integration and the collaborative arrangements advanced by local-level stakeholders that emphasise commonalities and mutual benefits. Meanwhile, external EU borders are characterised by wide-ranging modes of interaction and governance in respect of cross-border cooperation, and while in some cases, contacts are limited, there are several models and experiences of engagement, and indeed, collaboration. The current debate about the future status and workability of a border on the island of Ireland necessitates an examination of practices across pre-existing external EU borders. This paper responds to this requirement by presenting two case studies, namely, Spain-Morocco and Romania-Republic of Moldova.