At present UK citizens living overseas wanting to vote in UK elections have to complete paper forms and send them back to their local electoral office.
But the Cabinet Office is working on a service that would allow online registration, promising a simpler and quicker service, as well as a more reliable electoral register.
The scheme is still in its early stages and the Cabinet Office is seeking expat volunteers who are visiting Britain to help fine-tune the process.
Testing days will be held in Oxford on Thursday 31 October and London on Tuesday 17 December.
The new online registration option will have no impact on the current 15 year time limit for British expats living abroad from being able to vote in general parliamentary elections and European parliamentary elections.