The New Zealand Electoral Enrolment Centre maintains the New Zealand electoral rolls and conducts the Māori Electoral Option, which gives Māori the chance to choose between being on the Māori or general electoral roll. The centre is a self-contained business unit of New Zealand Post, under contract to the Minister of Justice. The centre has a team of Registrars of Electors - one for each electorate. The Registrars are responsible for compiling and maintaining the electoral rolls for their electorate, conducting enrolment update campaigns prior to all major electoral events, and encouraging eligible voters to enrol. This is to ensure the maximum number of eligible electors are enrolled to vote in Parliamentary, local council and District Health Board elections, by-elections, referendums and other polls.