Although most attorneys shrink away in terror when hearing that a supposedly breached contract was oral, MO law does honor certain oral contracts. Under the statute of frauds in Missouri, contracts generally must be in writing if they relate to (1) contracts which take in excess of a year to complete, (2) contracts for marriage, (3) certain contracts relating to an interest in real estate, and (4) certain estate contracts.
Independent of these statutory exemptions, however, oral agreements can be honored in a Missouri court. The difficulty, though, is that because the terms are not written it is difficult sometimes to ascertain the scope and nature of the agreement between the parties. In such cases, it falls to the Court to determine the terms, the existence of a breach, and whether there were damages.
The interplay between a required writing and oral contracts can often lead to interesting results. Many times contracts will have a written provision suggesting that if there is any amendment or cancellation of the contract (in part or in whole) then same would need to be in writing. There is some MO case law which suggests that such provisions are invalid. See Demean v. Ledl, 796 S.W.2d 415, 419 (Mo. Ct. App. 1990) (finding that an express provision in a written contract that no rescission or variation shall be valid unless it too is in writing is ineffective to invalidate subsequent oral agreements to the contrary).