Crossing the Irish Land Border after Brexit: The Common Travel Area and the Challenge of Trade

18 Pages Posted: 9 Mar 2018

See all articles by Imelda Maher

Imelda Maher

University College Dublin (UCD) - Sutherland School of Law

Date Written: March 8, 2018


“While the wind of change may be about to blow the precise direction in which it will blow cannot yet be determined so there is a level of uncertainty, as is evident from discussion about, for example, how Northern Ireland’s land boundary with Ireland will be affected by actual withdrawal by the United Kingdom from the EU.” Maguire J. Re McCord [2016] NIQB 85 para 107

Maguire J. was prescient in his observations as to the uncertainty surrounding the only land border there will be between the EU and the UK after Brexit. This raises the question of how to maintain an invisible border between Northern Ireland and Ireland, that invisibility being one of the most conspicuous outcomes of the Belfast/Good Friday Agreement. The answer to that question depends on how people and goods are dealt with post-Brexit. This in turn depends on the preservation of the long-standing Common Travel Area (CTA) and the nature of the trade relationship between the EU and UK post-Brexit and whether there are special arrangements in relation to Northern Ireland.

The border emerged as a key issue in the final hours of the first phase of the Brexit talks , highlighting how it is a complex challenge. That border has many dimensions. There is the obvious question of geography: a land border of almost 500 km that currently is invisible. There is the legal context of the Common Travel Area (CTA) between the UK and Ireland, which the UK and EU have agreed will continue after Brexit. There is the Belfast/Good Friday Agreement, which the same parties have agreed to protect. And there are the EU treaties and the future agreement between the UK and the EU following Brexit. There are the practical considerations of movement of people and goods across the border and there is the sensitive political context that this has been a violently contested border in the past.

This article explores these dimensions focussing mainly on the movement of people across the border. It analyses how the CTA will survive Brexit and specifically how a border can(not) be avoided if the UK leaves the customs union. It explores the CTA and December Joint Report between the UK and EU marking the end of the first phase of Brexit negotiations. It sets out the challenges for the law posed by the conflicting political ambitions of a soft border and a hard Brexit. Its conclusion is in the spirit of the comment of Maguire J. above: that while legal certainty is to be aspired to, that sometimes this is not possible. Even after the hoped for transitional arrangements between the EU and UK that may allow for some legal experimentation, the border and the CTA will necessarily look different after Brexit if the UK leaves the internal market and the customs union.

Divided into four parts, the article first provides some context in relation to economics and politics before turning to the opaque, legally obscure and practically significant CTA. The CTA and Brexit are then analysed before turning to the issue of how trade and in particular how the UK leaving the customs union will affect the guarantee of no hard land border before concluding.

Keywords: Brexit, Border, Northern Ireland, UK, Common Travel Area, EU, Good Friday Agreement, EU, Customs Union, Trade

Suggested Citation

Maher, Imelda, Crossing the Irish Land Border after Brexit: The Common Travel Area and the Challenge of Trade (March 8, 2018). UCD Working Papers in Law, Criminology & Socio-Legal Studies Research Paper No. 0318. Available at SSRN: or

Imelda Maher (Contact Author)

University College Dublin (UCD) - Sutherland School of Law ( email )

Dublin D04 V1W8
+1 716 4135 (Phone)


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