You qualify to register to vote if you are: a UK or Irish citizen
a qualifying Commonwealth citizen resident in the UK an EU citizen resident in the UK A qualifying Commonwealth citizen is someone who has leave to enter or remain in the UK, or does not require such leave. The definition of a 'Commonwealth' citizen includes citizens of British Crown Dependencies and British Overseas Territories.
https://www.yourvotematters.co.uk/can-i-vote/which-elections-can-i-vote-in Citizenship
British, Irish, Commonwealth, British Overseas Territory and British Crown Dependency citizens
British, Irish, and qualifying Commonwealth citizens who are living in the UK can vote in all elections taking place that cover the area where they live.