Utah Unilateral Mistake is an error made by one party to a contract that renders the contract voidable. This type of mistake can occur when one party of a contract has a mistaken understanding of the contract’s terms or has misunderstood the other party’s intentions. The mistake must be so serious that an ordinary person would not have agreed to the contract had they known the true facts. There are two types of Utah Unilateral Mistake: mutual mistake and unilateral mistake. Mutual mistake occurs when both parties to the contract make a mistake regarding a material fact, and unilateral mistake occurs when only one party to the contract makes a mistake regarding a material fact.