Voter Pre-Registration Deadline. The deadline to pre-register to vote for the primary election is 5 p.m. This applies to registration in person (including registration at driver’s license stations or agencies) or by mail. Voters may register online until 11:59 p.m. Exceptions: Mailed registration forms postmarked on or before the worry-free postmark date are considered on time even if they are received after 5 p.m. today. After today, a person may register to vote at the auditor’s office or at a satellite absentee voting station and vote an absentee ballot. The process is the same as for registering to vote on election day. Deadline to request an absentee ballot to be mailed is 5 p.m.