Express contracts are those in which two or more parties explicitly agree, orally or in writing, to a contract. For a plaintiff to prevail on breach of an express contract claim, the plaintiff must prove: (1) the existence and terms of a contract, (2) that plaintiff performed under the contract, (3) breach of the contract by the defendant, and (4) damages suffered by the plaintiff. Howe v. ALD Servs., Inc., 941 S.W.2d 645, 650 (Mo. Ct. App. 1997).
Implied contracts (aka quasi-contracts) are more vague and varied. An implied contract is created by a court to do justice even though it is clear that no promise was ever made or intended. Westerhold v. Mulenix Corp., 777 S.w.2d 257, 263 (Mo. Ct. App. 1989). Common implied contracts include unjust enrichment, quantum meruit and money had and received. Significantly, the existence of an express contract in a given situation usually prohibits a court from implying a contract.