To register to vote in Arizona you must meet the following qualifications (A.R.S. § 16-101):
Be a United States citizen
Be a resident of Arizona and the county listed on your registration
Be 18 years of age or older on or before the day of the next regular General Election
You should update your voter information if any of the following apply:
You recently moved to a new address
Your name has been legally changed
You would like to change your political party affiliation
