California Code, Civil Code - CIV § 3051a

That portion of any lien, as provided for in the next preceding section, in excess of three hundred dollars ($300) for any work, services, or care, or in excess of two hundred dollars ($200) for any safekeeping, rendered or performed at the request of any person other than the holder of the legal title, shall be invalid, unless prior to commencing any such work, service, care, or safekeeping, the person claiming such lien shall give actual notice in writing either by personal service or by registered letter addressed to the holder of the legal title to such property, if known.