I firmatari sono: Austrian Post, La Poste/De Post (Belgio), Post Danmark, Finland Post, La Poste (Francia), Deutsche Post, Hellenic Posts ELTA, Iceland Post, An Post (Irlanda), Poste Italiane, Entreprise des Postes Télécommunications (Lussemburgo), Norway Post, CTT Correios de Portugal, Correos y Telégrafos (Spagna), Sweden Post e The Post Office (Regno Unito).
The signatory parties are Austrian Post, La Poste/De Post (Belgium), Post Danmark, Finland Post, La Poste (France), Deutsche Post, Hellenic Posts ELTA, Iceland Post, An Post (Ireland), Poste Italiane, Entreprise des Postes Télécommunications (Luxembourg), Norway Post, CTT Correios de Portugal, Correos y Telégrafos (Spain), Sweden Post and The Post Office (United Kingdom).