Civic service (“service civique”) is a national tool created in 2010 to promote citizen engagement of youth from 16 to 25 years old. Heir to the voluntary civil program (“volontariat civil”) and then voluntary civil service (“service civil volontaire”), it conveys strong symbolical values, linked with the social and political functions previously attributed to national conscription. If associations have been the main entities for recruiting youth, a growing number of local authorities are beginning to sign agreements or establish partnerships with approved associations. Civic service is an incentive-based tool that is not within the remit of local authorities, so why do local authorities decide to support it? Based on a qualitative survey conducted in 2011 on four local authorities and Unis-Cité, an association specialized in civilian service, this article analyses the symbolical and organizational justifications of this mobilization. It shows that the constitutive flexibility of this tool, which functions as a true boundary object, allows for different interprÉtations for local authorities, between political advertising direction and organizational models choice.