A purchase order (PO) number is an alphanumeric code that is assigned to a particular request to buy something. Most often, PO numbers are used internally by businesses to track their own purchases. Some companies, however, will assign codes to all of their sales and will give PO numbers to their customers so the customers can track their orders. These codes can be in any alphanumeric format, and many companies will use specific letters or numbers to indicate certain things about the order, such as what is being sold, the location, the buyer and the date.
Use Within Companies
In many companies, a purchase order number is assigned after an employee or a department submits a request for the order of certain goods or services. The request usually is formally submitted to a purchasing agent using what is known as a requisition form. If the request is approved, a purchase order is created and is assigned a purchase order number. At that point, the order is placed with another company, which often records the buyer's PO number for inclusion on the order detail.
As the vendor prepares a shipping or packing list to go with the customer’s order, the PO number typically is included on the detail. This makes it possible for the buyer's receiving agent to verify the quantity and type of goods delivered and to confirm that the shipment is associated with a properly authorized order. The purchase order number also appears on the invoice and any other paperwork that the vendor gives to the customer. From this perspective, the PO number expedites the scheduling of payment to the vendor, and it allows the goods to be routed to the proper department.
The PO number also makes it possible for the company to apply the cost to the budget of the department that placed the order. It also provides the accounts payable department with verification that the expense is legitimate. Payment can then be rendered to the vendor.
The exact construction and length of a purchase order number will vary from one company to another. Many businesses that operate at multiple sites will use the first few characters of the code to identify the location that placed the order, such as "CHI" to represent a facility in Chicago. The next few characters might identify the specific department that placed the order, such as "RD" to represent the research and development department. Thus, the PO number for an order placed by a company's research and development department in Chicago might begin with "CHIRD," followed by other alphanumeric characters that provide more information about the order.
Companies usually structure their PO numbers in whatever manner works best with their internal tracking systems. Some also make use of dashes or spaces, which can help when only certain characters within a PO number need to be read for a specific purpose. In response to the wide variety of lengths and formats that can be used, many vendors configure the fields in their order tracking databases to allow any number of characters — even 30 or more — to be used in a purchase order number.