This paper presents a QA approach for joint programmes that has been developed by the Una Europa alliance. The Una Europa partners have developed a lean joint internal QA strategy for the joint programmes that seeks to build on existing practices within the partner institutions to the maximum extent. Trust between the partners is the key aspect of the joint QA strategy. The approach is based on the principles of verified trust, subsidiarity and core practices. From this follows a need for accountability and transparency. To ensure transparency, the partners share information on their internal QA methods in a "knowledge base". Furthermore, the partners have agreed on core practices for the smooth operation of the joint QA system: involvement of stakeholders, timing, scope, tools and communication. Based on this lean strategy, all Una Europa partners commit themselves to safeguarding the quality of joint programmes on a continuous basis.