Votes will be able to re-enrol and update their details via the internet in time for next year's general election.
Justice Minister Simon Power says the move will make it as simple as possible for people to take part in elections - particularly young people, 40% of whom aged between 18 and 24 are not enrolled.
He says online enrolment will use a robust identify verification service which is being developed by the Department of Internal Affairs.
It requires people to provide proof of identity before completing sensitive online transactions with government agencies.
Legislation on the matter will be introduced to Parliament in November.