The EC (EU) Procurement Directive 2004/18/EC, also known as the Classic Directive, defines a central purchasing body (CPB) in Article 1.10:
10. A ‘central purchasing body’ is a contracting authority which:
— acquires supplies and/or services intended for contracting authorities, or
— awards public contracts or concludes framework agreements for works, supplies or services intended for contracting authorities.
The definition of a central purchasing body builds on the concept of a contracting authority.
You can turn to the blog post EU procurement: Contracting authority, at:
The Recitals of the Procurement Directive present reasons for the consolidated legislation and for novelties. Recital 15 describes the central purchasing body (CPB):
(15) Certain centralised purchasing techniques have been developed in Member States. Several contracting authorities are responsible for making acquisitions or awarding public contracts/framework agreements for other contracting authorities. In view of the large volumes purchased, those techniques help increase competition and streamline public purchasing. Provision should therefore be made for a Community definition of central purchasing bodies dedicated to contracting authorities. A definition should also be given of the conditions under which, in accordance with the principles of non-discrimination and equal treatment, contracting authorities purchasing works, supplies and/or services through a central purchasing body may be deemed to have complied with this Directive.
Procurement Directive Article 11 sets out the optional nature of central purchasing bodies, but complying with the procurement rules is mandatory:
Public contracts and framework agreements awarded by central purchasing bodies
1. Member States may stipulate that contracting authorities may purchase works, supplies and/or services from or through a central purchasing body.
2. Contracting authorities which purchase works, supplies and/or services from or through a central purchasing body in the cases set out in Article 1(10) shall be deemed to have complied with this Directive insofar as the central purchasing body has complied with it.
The United Kingdom Office of Government Commerce has published OGC Guidance on Central Purchasing Bodies (March 2008):
The updated six page brochure (pdf) gives advice to contracting authorities entering into agreements with central purchasing bodies.