Collective membership, e.g. for associations of municipalities, is possible. For associations or agencies that are cooperating with more than 5 local authorities there is an option to become a relay structure. The relay structure (if not a member of Energie-Cités) pays 1000 euros and signs an agreement with Energie-Cités. Each local authority under control of the relay structure, with a population size larger than 10 000, then pays 500 euros. Settlements with a population smaller than 10 000 can join free. In new Member States each member of the relay organisation pays 250 euros.