Each EECS® certificate is uniquely identifiable, transferable and therefore tradable, and contains standard information on the source of the energy, and its method of production.

The Principles and Rules of Operation of the European Energy Certificate System (the EECS® Rules) defines a certificate as an electronic document which identifies the source and method of production of a unit of energy, and relates to a specific purpose – such as energy source disclosure or compliance with an obligation. It also prohibits certificate holders from separately claiming or conferring rights or title to any element of this benefit, and for this purpose.

Certificates are created, change owners and are eventually made untransferable under a carefully developed and managed control infrastructure, the EECS® Rules, as interpreted by each country or region according to its "Domain Protocol". The adequacy of this interpretation is assured by the other AIB members as a condition of membership.

EECS and the CEN standard

The EECS Rules provided the foundation of the proposed CEN standard. This version is the latest available, and is currently being revised prior to decision-making by CEN member organisations.