A subcontractor on a public works project is not paid. To make a claim on the prime contractor's payment bond, the subcontractor generally must:

解析

Because public property cannot be liened, the unpaid subcontractor's security is the prime's payment bond: it must give any preliminary notice its position requires and then sue on the bond, which Civil Code §9558 allows any time after it stops work but no later than six months after the stop-notice period in §9356 closes. Recording a lien against the school or city building is void from the start. Retention is money owed the prime under the prime contract, not a fund the agency pays claimants from. No agency consent is needed or available; the bond is a contract with the surety.