A. A municipality, county or school district may issue a blanket purchase order for:

B. Blanket purchase orders shall be prepared, filed, and encumbered in the manner provided for purchase orders and as authorized by law or regulation, except no written requisition shall be required for a blanket purchase order. Prior to payment, the requesting county officer shall verify the blanket purchase order by signature. Before transacting any purchase pursuant to a blanket purchase order, the order shall be submitted to the governing board for its approval. After satisfactory delivery of goods or services pursuant to a blanket purchase order, a vendor's invoice shall be submitted to and approved by the purchasing officer of a municipality or a school district or a county purchasing agent and forwarded for payment. An itemized list of goods or services purchased pursuant to the blanket purchase order shall be attached to the vendor's invoice if said invoice does not contain an itemized list of goods or services purchased pursuant to the blanket purchase order. Payment of invoices from vendors pursuant to a requisition and approved blanket purchase order issued pursuant to the provisions of this section shall be authorized by the encumbering officer.