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PO vs. Non-PO invoices: differences in the invoice approval process

Accounts payable is responsible for managing the processing of supplier invoices, from reception of the invoice, through coding and approvals, until the payment is posted in the ERP or financial system and ready for payment. There are two main types of supplier invoices: purchase order-based invoices, also called PO invoices, and expense invoices (or non-PO invoices).. Discover the differences between these two types, and why the invoice approval process differs depending on the type. 

The Difference Between PO and Non-PO Invoices 

The difference between PO and non-PO invoices lies in the purchase that generated the invoice. When a purchase requisition process is in place, the purchase will be triggered by a pre-approved purchase order (PO) that is sent to the supplier. In the case of purchases made outside the regulated purchase process, a non-PO invoice, also called an expense invoice, is sent from the supplier.  

What is a PO Invoice? 

A PO invoice should include the purchase order number and details of the goods or services provided as agreed between the buyer and supplier. Arriving at accounts payable, the PO invoice is matched against the purchase order to ensure that all details correspond. In most cases, companies will perform a three-way invoice matching to verify that the PO invoice details match both the purchase order and the goods receipt registered in the procurement or ERP system upon reception of goods or services. PO invoices typically include invoices for purchases of direct material. 

What is a Non-PO Invoice? 

Non-PO invoices do not have a purchase order associated with them, and are the result of spend outside a regulated procurement process. These types of invoices are often called expense invoices and are used for various indirect purchases.  

What is the Invoice Approval Process for PO vs. Non-PO Invoices? 

The accounts payable process is different for PO vs. non-PO invoices, mainly when it comes to the invoice approval process.  

A PO invoice is, in fact, a pre-approved invoice since the purchase, supplier, and amount were approved as part of the requisition process leading up to the purchase order. As a result, a PO invoice can be automatically processed for payment as long as all details match the information on the purchase order and goods receipt, without the need for manual review and approval. If a  deviation is identified in the matching process, the invoice will be sent to the buyer for review and action. 

A non-PO invoice, on the other hand, has not been pre-approved and will, therefore, need to go through an invoice approval process within the buying organization. Usually, the accounts payable team will apply coding and identify the correct approver, based on the information on the invoice and their best knowledge. If invoice details are scarce, this can be a tricky operation. Often, there is an internal approval hierarchy stipulating that invoices of a certain amount will need to pass multiple approval steps within that hierarchy. Once all necessary invoice approvals have been obtained, the invoice returns to accounts payable for final booking and payment. 

How Do You Automate Processing of PO vs. Non-PO Invoices? 

Today, accounts payable automation systems are available for companies of all sizes in every industry. There are considerable opportunities to automate the processing of both PO invoices and non-PO invoices, thereby removing manual, error-prone steps in the accounts payable process and achieving increased efficiency and control. In a modern, cloud-based solution, both types of invoices would be handled and automated by the same system, which also covers the invoice data capture via Optical Character Recognition (OCR) as well as the supplier payment process.

Intelligent matching of PO invoices can support an end-to-end fully automated and touchless process. When the data, obtained via OCR capture, on a PO invoice matches the data on the purchase order and goods receipt, the AP automation solution can perform automatic matching and no one in accounts payable (or anywhere else in the organization) needs to touch the invoice. 

The processing of non-PO invoices can also be highly automated by adopting a modern AP automation solution. Automation opportunities include: 

  • Automatic coding that is pre-configured in the solution, based on previous invoices from the same supplier or cost center 
  • Automatic distribution to the relevant approver, based on the organization’s approval hierarchy 
  • Automatic approval by matching recurring invoices (such as a lease) to the payment plan in a contract  

Companies benefit from automating the approval process of both PO invoices and non-PO invoices. The invoice approval process will be much more efficient and faster. And the entire organization will benefit from better control of the AP process, as well as increased visibility of financial metrics and company spend.

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