Jersey is not part of the United Kingdom, and has an international identity separate from that of the UK, but the UK is constitutionally responsible for the defence of Jersey. The definition of United Kingdom in the British Nationality Act 1981 is interpreted as including the UK and the Islands together. The European Commission have confirmed in a written reply to the European Parliament in 2003 that Jersey is within the Union as a European Territory for whose external relationships the UK is responsible. Jersey is not fully part of the European Union but has a special relationship with it, notably being treated as within the European Community for the purposes of free trade in goods.

What's the best answer to this question: is jersey a part of the united kingdom?
no