AZ SB1421

Amends Arizona Revised Statutes section 16-166 to add verification of the last four digits of an applicant's social security number as satisfactory evidence of United States citizenship for voter registration purposes.

Allows county recorders to accept social security number verification as an alternative to other citizenship documentation requirements, including driver's license, birth certificate, passport, naturalization documents, or tribal enrollment numbers.

Maintains existing requirements that persons already registered as of December 8, 2004 are deemed to have provided satisfactory evidence of citizenship and need not resubmit unless changing registration between counties.

Requires the bill to receive an affirmative vote of at least three-fourths of the members of each house of the legislature to take effect, per Arizona Constitution article IV, part 1, section 1.