JOIN currently has 20 member organisations, 16 of which are national charities from Austria, Cyprus, Denmark, England, Finland, France, Germany, Hungary, Italy, Latvia, Malta, the Netherlands, Poland, Sweden and Switzerland, plus the St John Eye Hospital in Jerusalem.

The services provided by the member organisations vary substantially, they all share a common approach to humanitarian welfare and social aid.

JOIN's member organisations are active in the areas of emergency medical rescue,[1][2][3] patient transport services,[4][5][6][7][8][9] first aid,[10] first aid training,[11][12] international humanitarian assistance,[13][14] youth work,[15][16][17][18][19][20][21] food and clothing donations, educational institutions, patient repatriation,[22] services for the disabled,[23][24][25][26] elderly care[27][28][29] and many others.

Upon request and on behalf of JOIN member organisations, the office regularly takes part in various meetings at European level, for instance in the areas of humanitarian assistance, development cooperation, civil protection, care, research and innovation.

In addition, the Secretariat maintains close contact with NGO partners, the Brussels offices of national and regional representations and with the members of the Orders of St John who work in the European capital.