Register as an overseas elector
If you are a British citizen living abroad, you are still entitled to vote in UK Parliamentary Elections and Referendums.
You will need to register to vote by going to GOV.UK.
Due to legislation changes for overseas electors, restrictions have been lifted granting those who moved abroad 15 plus year ago eligability to register to vote. Click on the below link for more information.
Electoral Commission
To ensure you can vote in future Parliamentary elections, you need to apply online for a postal or proxy vote.
Overseas Postal Application
Overseas Proxy Application