It means British or Irish citizens can travel freely within the CTA without seeking immigration permission from the authorities.
British citizens in Ireland and Irish citizens in the UK have associated rights and entitlements including access to employment, healthcare, education, social benefits, as well as the right to vote in certain elections.
The governments of Ireland and of the United Kingdom signed a Memorandum of Understanding reaffirming their joint commitment to the Common Travel Area (CTA on 8 May 2019.
Neither Irish citizens in the UK nor British citizens in Ireland are required to take any action to protect their status and rights associated with the CTA. Both governments are committed to undertake all the work necessary, including through legislative provision, to ensure that the agreed CTA rights and privileges are protected.
You can find out more about the CTA and the rights of British and Irish citizens via the following link below: