How long do I have to sue for breach of contract in California?

Four years for a written contract; two years for an oral one. Code of Civil Procedure section 337 sets the four-year period for actions on a contract, obligation, or liability founded on a written instrument, while section 339 gives oral agreements two years. The clock generally starts at breach — not when the contract was signed, and not necessarily when the damage is felt — though continuing performance and installment obligations can create separate accrual dates for each missed payment. Watch three common modifiers. First, parties may shorten the period by contract, and commercial agreements frequently do. Second, claims styled as fraud run three years from discovery (section 338(d)), and unfair competition claims under Business and Professions Code section 17200 run four. Third, a written acknowledgment or part payment can restart the clock on a debt (section 360). Sales-of-goods contracts follow the Commercial Code's own four-year rule (Commercial Code section 2725).

Authority: Cal. Code Civ. Proc. § 337