The deadline to update your voter registration or register to vote in an upcoming election is midnight on the 29th day before the election. For the 2020 Presidential Preference Election, the deadline to register or update your registration is midnight on February 17, 2020. For the 2020 State Primary Election, the deadline to register or update your registration is midnight on July 6, 2020. For the 2020 General Election, the deadline is midnight on October 5, 2020. To see all voter registration deadlines, including for local elections, visit Arizona.Vote. All voter registration forms sent by U.S. mail must be postmarked on or before the deadline.