If you have evidence that a voter is wrongly registered, you may challenge his/her registration. The voter will be notified and will have a chance to defend his/her registration. After a preliminary investigation to weed out frivolous challenges the Registrar of Voters will mark the voter's registration as being disputed, and after a thorough check the voter will either be disqualified or reinstated. Because of the way the Ballot Ticket is recorded, a disqualification can be effective even after the election.