Difference between purchase order and invoice
A purchase order (PO) is a document that is issued by a buyer to a seller for the purpose of indicating their intention to purchase certain products or services. An invoice is a document issued by a seller to a buyer summarising the products or services that they have purchased (or have agreed to purchase).
Whereas POs are sent before delivery or payment, invoices can be sent before or after the delivery of products or services, and typically include a payment due date. An invoice can also be sent after a PO has been agreed.
An invoice becomes a legally-binding document, detailing a debt owed by the buyer to the seller, once it has been agreed to.
The details contained on a PO and an invoice are similar. The invoice will usually reference a PO number (if there has been one) to assist with record keeping and avoid confusion. However, an invoice will usually not include the technical details of the order might be included on a PO.
 Related articles on Designing Buildings Wiki
Featured articles and news
This article explains the Buildings Regulations completion certificate, what it is, and when its needed.
Graphene has many potential applications, but when will it start being used in civil engineering?
Increasing productivity – now more than ever as we lead up to Brexit – should be the sector’s number one priority in 2018.
Carillion's collapse causes Construction Leadership Council to delay the construction sector deal report.
Urban Heritage, Development and Sustainability: international frameworks, national and local guidance.
What will the General Data Protection Regulations (GDPR) mean for you when they come into force in May?
Business Secretary chairs a new taskforce to monitor and advise on mitigating the impacts of Carillion’s liquidation.
Sir John Armitt is appointed the new chair of the National Infrastructure Commission.
High quality and high density homes - is it what we need or is it storing up trouble?
Government announces its intention to strengthen planning rules to protect music venues and neighbours.
National Audit Office reports that there is little evidence that PFI offers better value than other forms of contracting.
What is liquidation and how does it apply to contractors in the construction industry?