Utah Code § 20A-9-805: Closed primary -- Determining party affiliation -- Changing party affiliation.

(1) If a registered political party has restricted voting for its presidential candidates as authorized by Subsection 20A-9-802(3)(b), the lieutenant governor shall direct the county clerks and other election officials to allow only those voters meeting the registered political party's criteria to vote for that party's presidential candidates.

(2)

(a) For each individual who registers to vote, the county clerk shall:

(i) record the party affiliation designated by the individual on the voter registration form as the individual's party affiliation; or

(ii) if no political party affiliation is designated by the individual on the voter registration form, record the individual's party affiliation as "unaffiliated."

(b) Any registered voter may designate or change the voter's political party affiliation by complying with the procedures and requirements of Section 20A-2-107 or Section 20A-9-808.