Utah Code § 58-37-114: Burden of proof in proceedings on violations.

(1) It is not necessary for the state to negate any exemption or exception set forth in this chapter or in Title 76, Chapter 18, Part 2, Offenses Concerning Controlled Substances, in any complaint, information, indictment or other pleading or trial, hearing, or other proceeding under this chapter or in Title 76, Chapter 18, Part 2, Offenses Concerning Controlled Substances, and the burden of proof of any exemption or exception is upon the person claiming the benefit of the exemption or exception.

(2) In absence of proof that a person is the duly authorized holder of an appropriate license, registration, order form, or prescription issued under this chapter, a person shall be presumed not to be the holder of a license, registration, order form, or prescription, and the burden of proof is upon the person to rebut the presumption.