Eligible voters are being encouraged to ensure they are on the electoral register in time for the European election in June.
Just over one million people have registered
The Electoral Commission launched its advertising campaign on Monday to remind people of rolling registration, which means that the electoral register is updated monthly.
The closing date for registration is 8 April.
Seamus Magee of the Electoral Commission said young people, students and people with disabilities were being targeted in particular by the campaign.
It emerged last month that the new Northern Ireland Electoral Register was down by more than 28,000 electors compared to the one used in last year's Assembly elections.
Just over one million people have registered.
A report in December last year said measures to combat voting fraud in Northern Ireland had a negative impact on young people and those in poorer areas.
The Electoral Commission said this measure tended to have an adverse impact on disadvantaged, marginalised and hard to reach groups.
The report also called for a review of the special hearings procedure for those who want to be added to the electoral register.
The need to register every year was brought in by the Electoral Fraud Act 2002.
In the past, one form was given to every household, but now everyone has to register individually.
The four main parties in Northern Ireland have now chosen their candidates to stand in the 10 June election.