Almost a fifth of eligible voters in Northern Ireland are incorrectly registered or not registered at all, according to the Electoral Commission.
A canvass of electors published by the Electoral Commission said substantial improvements have been made to the quality of the electoral registers in the region.
However, it pointed out almost 300,000 people in Northern Ireland are still either incorrectly registered to vote or missing completely.
It said this would mean they may not be able to vote if an election was called now.
The commission said young people, private renters and those who have recently changed address continue to be less likely to be correctly registered to vote.
The commission is calling on the UK Government to create “clear legal gateways” for government departments and public bodies to share data on potentially eligible voters to further improve accuracy and completeness of the electoral registers.
It said such reform could enable the chief electoral officer to register voters directly or send them invitations to register.
Cahir Hughes, head of the Electoral Commission in Northern Ireland, said: “While the increased levels of accuracy and completeness of the electoral registers in Northern Ireland are welcome, almost 300,000 people are still either missing from the registers or not correctly registered to vote.
“While some may not want to participate in elections, for many people it is a consequence of an outdated registration system that disproportionally affects private renters and young people.
“Changes to the current electoral registration system are needed.
“A more automated form of voter registration could see applications made at the same time as other tasks, such as updating the address on your driver’s licence or when enrolling at university.”
The report shows the accuracy and completeness of the electoral registers across Northern Ireland, including breakdowns by age and gender.
It also sets out a range of options for how specific data sources could be used to improve the system.
