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Purchase order (PO)

A purchase order is the county's official written authorization to buy specific goods or services at an agreed price. Most counties won't pay an invoice without one.

For many county purchases, especially smaller ones, the purchase order is the contract. It lists the items, quantities, prices, delivery address and the PO number you must put on your invoice.

Before you ship or start work

Make sure you have a PO, or a signed contract for larger work. A verbal request from a department doesn't commit the county to pay. Many counties' purchasing rules say that unauthorized purchases aren't the county's obligation.

Blanket and term POs

For repeated purchases under a term contract, counties may issue a blanket PO with a maximum amount, then order against it.

Last reviewed Oct 30, 2026. This is general information, not legal advice. Laws and thresholds change; check the current statute and the bid documents.