Utah Code § 58-55-601
When making any payment to a materialman, supplier, contractor, or subcontractor with whom he has a running account, or with whom he has more than one contract, or to whom he is otherwise indebted, the contractor shall designate the contract under which the payment is made or the items of account to which it is to be applied. When a payment for materials or labor is made to a subcontractor or materialman, the subcontractor or materialman shall demand of the person making the payment a designation of the account and the items of account to which the payment is to apply. In cases where a lien is claimed for materials furnished or labor performed by a subcontractor or materialman, it is a defense to the claim that a payment was made by the owner to the contractor for the materials and was so designated and paid over to the subcontractor or materialman, if when the payment was received by the subcontractor or materialman, he did not demand a designation of the account and of the items of account to which the payment was to be applied.
Utah Code § 58-55-601