A few months ago I decided to register as a UK overseas voter. My decision to do so was based on the outcome of the last election and the subsequent possibility of being eligible to vote in a referendum on electoral reform. It is possible the only national election in which my vote will count (under the present first past the post, winner takes all, yah boo sucks system - the FPP-WTA-YBS).
I duly went to the registration website, downloaded an application form, filled it in, got a fellow Brit ex-pat to witness my declaration, sent the form back, went on holiday and then forgot all about it. Today I got an email from my former local electoral registration office saying that they couldn't find me on their lists. I immediately went to Wikipedia - worked out which election I would have last voted in and asked them to check the register for that year. And - hey presto - they found me. I'm now in the system..
Practical tips. British citizens living overseas can register for an overseas vote if they have been registered on a UK electoral roll within the past 15 years.
Visit 'about my vote'. Check the options, download the form and find the address of your previous electoral registration office.
Mind you - theres no guarantee you will get to use your vote. Eligibility for voting in the referendum has not yet been decided - and when a snap election is called it is highly possible that the ballot paper will not reach an overseas voter in time for them to return it. We can but try though.