How the kingdom is actually arranged

The United Kingdom of Great Britain and Northern Ireland is England, Scotland, Wales and Northern Ireland. Great Britain is the island: England, Scotland and Wales. Britain, in ordinary speech, is often used for the whole state, which is slightly wrong and universally understood.

About 69 million people live here. England holds the large majority, Scotland a little over five million, Wales a little over three, Northern Ireland just under two. London is a city-region of its own, not a fifth nation, though it sometimes behaves like one.

The Isle of Man, Jersey and Guernsey are Crown Dependencies. They are not part of the United Kingdom and not in the EU. British Overseas Territories — Gibraltar, the Falklands, Bermuda and the rest — are not part of the UK either. The Republic of Ireland is a separate sovereign state. You can cross into it from Northern Ireland without a passport in ordinary circumstances, but it is not British.

If a briefing, a map or a tour lumps “the British Isles” into one political unit, it is being geographic, not constitutional. Index UK indexes the state, and notes the neighbours when a journey crosses them.

Laws, bank holidays, school terms and even some tickets change at the borders. Scotland’s outdoor access rules are broader than England’s. The Senedd, not Westminster, runs most of daily life in Wales. Alcohol licensing, education and health are devolved. A “UK bank holiday” is often an English and Welsh one; Scotland keeps its own calendar, including a January holiday England does not.

Currency is the pound sterling everywhere in the UK. Scottish and Northern Irish banks print their own notes. They are legal sterling, and they are sometimes frowned at in English tills. Cards work. Pounds from the Bank of England are the least surprising paper.