Belgian Regions (three Regions), Communities (three Communities) and Municipalities are represented at the CoR.

Belgian regions and communities may participate in the Council of the European Union. Matters are divided into those predominantly concerning the federal, the regional, or the community governments; representation in the Council is arranged accordingly, either by only one level representing Belgium or by a joint delegation. Where there is exclusive competence, the respective level nominates the representative and assistant representative. In other cases (including the last two), the predominant government nominates the representative and the other government the assistant. The Coordination of Belgian positions within the EU is undertaken by the Directorate for European Affairs in the Foreign Ministry. Where regional or community matters are concerned, agreement requires the consent of all the relevant governments. If this is not forthcoming, the matter can be referred to the Inter-Ministerial Conference for Foreign Policy. If agreement is not reached, Belgium has to abstain in the EU Council.