Residence rights of UK citizens
People who are citizens of the United Kingdom (UK) are entitled to live in Ireland without any conditions or restrictions. Unlike the citizens of other countries, they are not subject to the Aliens Act 1935 or to any orders made under it. This means that a UK citizen does not need a visa, any form of residence permit or employment permit in Ireland. They are entitled to move to Ireland from any country and they may move to Ireland to work or to retire. Unlike other EU citizens, UK citizens may retire to Ireland without having to establish that they have sufficient resources or that they have private health insurance.
In general, while living in Ireland, UK citizens are entitled to avail of public services on the same basis as Irish citizens living in Ireland. They are entitled to vote in Irish elections with the exception of Presidential elections and referendums.
The right of UK citizens to live in Ireland derives from Irish law. UK citizens also have rights under the EU freedom of movement legislation. These rules do not expand the rights of UK citizens themselves (since their rights are more extensive than those of other EU citizens) but they may be relevant for the family members of UK citizens living in Ireland. Family members of UK citizens who are not themselves EU citizens may be able to move to Ireland to live with them.
UK citizens do not need a passport when travelling to Ireland from within the Common Travel Area. However they can be asked for photo identification and proof that they are a UK citizen. They do need a passport if travelling from outside the Common Travel Area.
The UK government has a short guide for UK citizens living in Ireland and travelling to Ireland.
Living in Ireland
UK citizens are entitled to live in Ireland. In general, people who are not Irish citizens are subject to the Aliens Act 1935 as amended. UK citizens are not. While resident in Ireland, they are subject to the criminal and civil law in the same way as all other residents. Among other things, this means that they may be arrested for crimes allegedly committed in other countries and may be extradited.
Entitlement to health services
UK citizens who are resident in Ireland are entitled to health services in the same way as Irish citizens who are resident. This means that they may avail of public health services if they are “ordinarily resident”.
UK citizens resident in Ireland whose income is from a UK source and who do not have any income from Ireland may be entitled to a medical card regardless of their means. (Under EU rules, if you are getting a social security pension from another EEA country or Switzerland, or if you are working and paying social insurance in one of these countries, you may qualify for a medical card if you are ordinarily resident in Ireland, provided you are not subject to Irish social security legislation.)
Social welfare payments
UK citizens living in Ireland are eligible to apply social welfare payments in the same way as Irish citizens living in Ireland.
With all social welfare payments in Ireland, you must satisfy the rules for each scheme to qualify. You must also be habitually resident in Ireland to qualify for many of the means-tested social welfare payments.
Residence in the Common Travel Area is treated the same way as residence in Ireland for the purposes of the habitual residence condition (HRC). However, UK citizens who have recently moved to Ireland may find it more difficult to establish that their main centre of interest is in Ireland.
UK citizens living in Ireland are entitled to vote in national, local and European Parliament elections if they meet the other requirements. They are not entitled to vote in Presidential elections or referendums.