A minor can not legally make contracts. A contract made by a minor will not be enforced against that minor while the minor is under 18 years old Once a minor turns 18, he or she can either reject the contract or keep the contract. If the 18 year old agrees to keep the contract, it becomes valid. In most cases, contracts made by minors will not be enforceable against the minor’s parents. A parent will only be responsible for the contract of a minor if the contract is made for necessities, for example, food or medical treatment.