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.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
The 5 elements of seiri, seiton, seiso, seiketsu and shitsuke.
Shading for housing, a design guide
A look back at embedding a new culture of shading.
The Architectural Technology Awards
The AT Awards 2025 are open for entries!
ECA Blueprint for Electrification
The 'mosaic of interconnected challenges' and how to deliver the UK’s Transition to Clean Power.
Grenfell Tower Principal Contractor Award notice
Tower repair and maintenance contractor announced as demolition contractor.
Passivhaus social homes benefit from heat pump service
Sixteen new homes designed and built to achieve Passivhaus constructed in Dumfries & Galloway.
CABE Publishes Results of 2025 Building Control Survey
Concern over lack of understanding of how roles have changed since the introduction of the BSA 2022.
British Architectural Sculpture 1851-1951
A rich heritage of decorative and figurative sculpture. Book review.
A programme to tackle the lack of diversity.
Independent Building Control review panel
Five members of the newly established, Grenfell Tower Inquiry recommended, panel appointed.
Welsh Recharging Electrical Skills Charter progresses
ECA progressing on the ‘asks’ of the Recharging Electrical Skills Charter at the Senedd in Wales.
A brief history from 1890s to 2020s.
CIOB and CORBON combine forces
To elevate professional standards in Nigeria’s construction industry.
Amendment to the GB Energy Bill welcomed by ECA
Move prevents nationally-owned energy company from investing in solar panels produced by modern slavery.
Gregor Harvie argues that AI is state-sanctioned theft of IP.
Experimental AI housing target help for councils
Experimental AI could help councils meet housing targets by digitising records.
BSRIA Occupant Wellbeing survey BOW
Occupant satisfaction and wellbeing tool inc. physical environment, indoor facilities, functionality and accessibility.