California Code, Business and Professions Code - BPC § 6091

If a client files a complaint with the State Bar alleging that his or her trust fund is being mishandled, the State Bar shall investigate and may require an audit if it determines that circumstances warrant.

At the client's written request, the attorney shall furnish the client with a complete statement of the funds received and disbursed and any charges upon the trust account, within 10 calendar days after receipt of the request. Such requests may not be made more often than once each 30 days unless a client files a complaint with the State Bar and the State Bar determines that more statements are warranted.