ACCU is the forum for discussion between the CERN Management and the representatives of the CERN Users community (the Delegates) to review the practical means taken by CERN for the work of Users of the Laboratory.

This concerns in particular the working conditions and the arrangements for technical support to the CERN Users. Questions dealing with the scientific programme of CERN do not fall under these terms of reference.

There are 1 or 2 Delegates from each Member State (2 Delegates from the large Member States), 1 Delegate from each of the Associate Members, 4 Delegates from non-Member States (NMS), and 2 from CERN. The 4 NMS Delegates act ad personam, they don't represent a country but should come from the Users' community in a specific region. The Chairperson of ACCU is elected from among the Delegates of the Committee.

The Delegates of ACCU are active Users of the CERN Laboratory, familiar with the day-to-day life at CERN and well known and respected within their Users community. They are appointed by the Director General following a nomination by the respective scientific authority in their country.

ACCU meetings are held four times per year. Meetings are closed but agenda, minutes and uploaded presentations are open and are accessible by anyone, with a few exceptions only. The meetings of ACCU are attended by a member of the Directorate, often the Director General, by the Head of the Users' Support, who also acts as ACCU Secretary, as well as by other members of the CERN Management and Departmental Representatives. A representative of the CERN Staff Association also attends the meetings.