The statute of limitations is the time a party has to bring a lawsuit and is a common defense asserted at trial. In California, the statute of limitations for a breach of a written contract is four years and two years for the breach of an oral contract. However, the statute of limitations generally begins to run when the breach of the contract occurs. For example, if your friend has been making payment toward the loan, but recently stopped, then you would still have a viable claim within the statute of limitations. In addition, if your friend completes an act to revive the debt, like recently making a payment or agreeing to sign a contract, the statute of limitations will start over again. If you have additional questions about your ability to file a civil lawsuit against your friend to enforce this debt, visit the Sacramento County Law Library’s website, http://www.saclaw.lib.ca.us/pages/filing-a-lawsuit.aspx.