Prior to 16th January this year British Citizens living abroad could only register to vote in elections to the UK parliament for up to 15 years after the left the UK. This rule has now been abolished and British citizens can now register to vote in the UK regardless of how long they have been living abroad, or when they were last registered to vote. Registrations can be done online (with the exception of Northern Ireland) and will be valid for 3 years before you have to re-register. You will need to register again before then if you’ve changed your name, address or nationality within the 3 years.
Registering online is a simple step by step process and takes around five to ten minutes following the instructions at gov.uk/register-to-vote. You may need your UK passport, National Insurance number and details of the address where you were last registered to vote.
If you have never been registered, you will need to prove when and where you previously lived in the UK. You can see more information at www.electoralcommission.org.uk and at commonslibrary.parliament.uk