The Common Travel Area (CTA) is a travel zone comprising the Republic of Ireland, the United Kingdom, the Isle of Man and the Crown Dependencies of Guernsey, Jersey and the Northern Isles. With certain exceptions, the CTA's internal borders are subject to minimal or non-existent border controls and can normally be crossed by British and Irish citizens with minimal identity documents.
With Scotland's departure from the United Kingdom, Scotland left the CTA. Whilst there have been requests by Scotland to join the CTA, the UK has so far refused.