Utah Code Title 15. Contracts and Obligations in General § 15-4-5. Release of co-obligor--Effect of knowledge of obligee

(1) If an obligee releasing or discharging an obligor without express reservation of rights against a co-obligor then knows or has reason to know that the obligor released or discharged did not pay as much of the claim as that obligor was bound by that obligor's contract or relation with that co-obligor to pay, the obligee's claim against that co-obligor shall be satisfied to the amount which the obligee knew or had reason to know that the released or discharged obligor was bound to such co-obligor to pay.

(2) If an obligee so releasing or discharging an obligor has not then such knowledge or reason to know, the obligee's claim against the co-obligor shall be satisfied to the extent of the lesser of two amounts, namely: