California Code, Public Contract Code - PCC § 20459

Any person furnishing materials, provisions, provender or other supplies used in, upon, for or about the performance of the work contracted to be executed or performed, or any person renting or hiring teams or implements, or machinery for, or contributing to, the work to be done, or any person who performs work or labor upon the same, or any person who supplies both work and materials and whose claim has not been paid by the contractor or by the subcontractors of the contractor may, at any time within 30 days from the date of the recordation of the assessment file with the superintendent of streets a verified statement of his claim, together with a statement that the same, or some part thereof, has not been paid.