SCI cooperates with partner organisations all over the world. Currently SCI has active partnerships with more than 80 organisations spread over Europe, Africa, Asia, Mediterranean region, North and Latin America.

Partner organisations are independent but like-minded organisations that have in common with SCI that they also run international voluntary projects. SCI branches and partners cooperate in many ways, but mainly through volunteer exchange.  Partner organisations can also actively participate in an international working group, or cooperate with other partners and branches in organising a campaign on a specific theme.  They are however not members of SCI and therefore they have no voting rights at the most important meeting of SCI, the ICM.