Generally, oral or verbal contracts are indeed legally enforceable, but there's a fundamental problem: how do you prove what was agreed upon? That's why written contracts are far more useful, because everything's down in, well, black and white. Oral contracts are just as valid as written ones, but some jurisdictions either require a contract to be in writing in certain circumstances (for example where real property is being conveyed), or that a contract be evidenced in writing (though it may be oral). An example of the latter being the requirement that contract of guarantee be evidenced in writing that is found in the Statute of Frauds. Similarly, the limitation period prescribed for an action may be shorter for an oral contract than it is for a written one." An oral contract is often provable by action taken by one or both parties which is obviously in reliance on the existence of a contract. The other significant difference between oral and written contracts is that the time to sue for breach of an oral contract (the statute of limitations) is sometimes shorter. For example, California's limitation is two years for oral compared to four for written, Connecticut and Washington three for oral rather than six for written, and Georgia four for oral instead of 20 for written