Mark your calendars and brush up on everything you need to know about mail-in and early in-person voting, including the first day you can cast your ballot in the 2020 election. To register in New Jersey, you must be: a United States citizen, at least 17 years old, though you may not vote until you have reached the age of 18, a resident of the county for 30 days before the election, and a person not serving a sentence of incarceration as the result of a conviction of any indictable offense under the laws of this or another state or of the United States. Registrants must complete a Voter Registration Application and/or Party Affiliation Form. Mail or deliver the Voter Registration Application and/or Party Affiliation Form to the County Commissioner of Registration or Superintendent of Elections for your county. The registration deadline to vote in the next election is 21 days prior to the election day - Tuesday, October 13th. There are 74 days left until Election Day, Tuesday, Nov. 3..