(a) All invoices or vouchers shall be billed to the State of California or to a particular department, board, commission, agency, or officer thereof and shall be presented for allowance in accordance with the procedure set forth in these rules and regulations.

(b) Invoices or vouchers not on printed bill heads shall be signed by the vendor or person furnishing the supplies or service.

(c) Every invoice for the purchase of materials, supplies or equipment shall show the purchase order number under which the materials, supplies or equipment were purchased.

(d) Every invoice shall be properly itemized before a claim, based thereon, is filed for payment.

(e) Where claims for services are rendered under a contract, the claims shall show the agency contract number.

(f) An invoice will not be required from a lessor if the applicable lease is on file with the State Controller and the State agency submits an itemized claim for payment in a form approved by the State Controller.