Los siguientes socios han participado hasta ahora en la elaboración del proyecto:
- Alpha International,
- Basisgemeinde Deutschland,
- Centre Orthodoxe de Chambésy,
- Ceras Project,
- Community of Chemin Neuf,
- Church of Sweden,
- Commission of Bishops’ Conferences in the European Union,
- Community of Grandchamp,
- Council of Bishops’ Conferences of Europe,
- Conference European Churches,
- Dicastery for Laity, Family and Life,
- Dicastery for Promoting Christian Unity,
- Focolari,
- Fondacio,
- For an ecological awakening,
- French Conference of Religious,
- French Protestant Federation,
- German Evangelical Alliance,
- Glauben und Gesellschaft,
- Global Christian Forum,
- Greek Orthodox Metropolitan Exarchate Europe,
- International Young Catholic Students, JC2033,
- Jesuits French Province,
- Justice & Peace Europe,
- L’Arche in France,
- Community of L’Emmanuel,
- Ligue pour la Lecture de la Bible,
- Lutheran Church of Estonia,
- Methodist Church UK,
- Mouvement Laudato Si,
- Old Catholic Church Utrecht Synod,
- Pontifical Missionary Works in Lebanon,
- Sant’Egidio,
- Sisters of St Andrew,
- Synod Secretariat,
- Together for Europe,
- Ukrainian Greek-Catholic Church France,
- Uniting Protestant Church of France,
- World Council of Churches,
- World Lutheran Federation,
- World Methodist Council,
- Catholic Association for Ecumenism Netherlands,
- Catholic Youth Service Universities Austria,
- Catholic Youth Service France,
- Catholic Youth Service Hungary,
- Catholic Youth Service Poland,
- Catholic Youth Service Portugal,
- Catholic Youth Service Slovenia,
- Catholic Youth Service Spain,
- Catholic Youth Service Switzerland
Además, en Roma participan los siguientes socios:
- The Vicariate of Rome,
- Confederation of Italian Evangelical Churches,
- The Waldensian Church,
- The Methodist Church,
- The Anglican Centre,
- Rumanian Orthodox Church,
- Serbian Orthodox Church,
- Faith and Light,
- The Episcopalian Church,
- Azione Catollica
- Caritas Roma
- Centro Astalli
- Centro Pro Unione
- Federation of Evangelical Churches in Italy (FCEI)
- Jesuit Refugee Service
- Missionaries of Africa
- Partners of the International Day of Prayer and Awareness against Human Trafficking
- Pietre Vive
- Pontifical Gregorian University
- Pontifical Institute for Arabic and Islamic Studies
- Sisters of Charity of St Jeanne Antide
- Talitha Kum International
- The Clewer Initiative
Estos socios están ayudando con la logística del fin de semana de Together:
- All Food – suministrando alimentos para la comida para llevar del 30 de septiembre.
- Ecozema Società Benefit – suministrando cubiertos Mater-Bi y envases de PLA y celulosa.
- Oikuria – responsable de la planificación de la recogida de residuos y de la formación de los voluntarios.
- Sisifo Società Benefit – concepción del proyecto Tutela de la Creación y coordinación de los socios de sostenibilidad.
- Confragricoltura – suministro de árboles, arbustos y matas para la decoración de la plaza de San Pedro durante la vigilia ecuménica de oración del 30 de septiembre.
- Asociación KRO-NCRV – suministro de 4.100 plantas de ciclamen para la decoración de la Plaza de San Pedro durante la vigilia ecuménica de oración del 30 de septiembre y después para el Aula Paolo VI durante el Sínodo.