Collaboration between teachers and librarians is necessary to fulfil the intention of the regulations of the Norwegian Education Act. In-depth semi-structured interviews with 12 school librarians in upper secondary school (with students aged 15-19), reveal that library tasks, and especially collaboration with teachers, are not embedded in formal documents. The librarians’ teaching activities are to a small extent dependent on formal collaboration, but are often based on familiarity and acquaintance, and therefore person-dependent. Organizational placement varied among the librarians, and they were pragmatic about who they should report to. To be organized in sections together with teachers was considered to be a good position for collaboration, but on the other hand might hinder collaboration with teachers in other sections. The librarians appreciated the freedom they had to run the library, however many of them missed support from their leaders. Information channels like Teams and timetables are important sources for librarians to stayupdated and enable them to target requests to teachers.