Letters are dropping into homes in an annual operation alerting householders to check the names of those already on the register and report on a form any people moving in or out.
The new list comes into force in December and runs for a year.
Polls are scheduled on May 5 for the Scottish Parliament, Welsh and Northern Ireland assemblies, all but a handful of cities, boroughs and districts in England outside London, Northern Ireland local authorities and elected mayors in Bedford, Mansfield, Middlesbrough and Torbay.
Additionally there will be contests for most of England's parish and town councils.
A nationwide referendum is also planned for the same day on whether to switch to an Alternative Vote system for general elections.