Common Travel Area in the context of "Travel visa"

The visa policy of Ireland is set by the Government of Ireland and determines visa requirements for foreign citizens. If someone other than a European Union, EFTA or Common Travel Area citizen seeks entry to Ireland, they must be a national of a visa-exempt country or have a valid Irish visa issued by one of the Irish diplomatic missions around the world.

Although Ireland is a member of the European Union, it is not part of the Schengen Area and therefore sets its own visa policy. Ireland also operates the Common Travel Area with the United Kingdom, the Channel Islands and the Isle of Man which specifies open borders between the countries and territories. Established in 1923, it permits British and Irish citizens freedom of movement around the Common Travel Area and to cross its borders with minimal or no identity documents.

The Republic of Ireland–United Kingdom border, sometimes referred to as the Irish border or British–Irish border, runs for 499 km (310 mi) from Lough Foyle in the north-west of Ireland to Carlingford Lough in the north-east, separating the Republic of Ireland from Northern Ireland.

Border markings are inconspicuous, in common with many inter-state borders in the European Union. As the two states share a Common Travel Area and (as of 2021) Northern Ireland (the only exception within the UK and only in some respects) and the Republic of Ireland are participants in the European Single Market, the border is essentially an open one, allowing free passage of people since 1923 and of goods since 1993. There are circa 270 public roads that cross the border. Following the United Kingdom's exit from the European Union, this border is also the frontier between the EU and a non-member country. The Brexit withdrawal agreement commits all involved parties to maintaining an open border in Ireland, so that (in many respects) the trade frontier is the Irish Sea between the two islands. This de facto division of the United Kingdom is described, especially by Unionists, as "the Irish Sea border".