Sustainability reporting is a mostly voluntary activity that has gained great adherence in the corporate world. In examining the determinants of this activity research has focused on external company factors, providing mixed results. Hence, his study concentrates on internal factors by exploring how companies manage their sustainability reporting process. Using a qualitative research design we examine the internal factors that are associated with sustainability reporting of six Dutch companies with exemplary reports, as determined by two sustainability reporting benchmarking schemes. Additionally, the reports of the case companies are content analysed and their benchmark scores are scrutinised. Results demonstrate that, despite their top ranks in the schemes, the constellations of structures, systems and processes with which sustainability reporting is managed, varies across companies. Remarkably, for half of the sample companies sustainability (reporting) is not part of the day-to-day activities, but rather decoupled. Based on these findings, a typology of sustainability reporting is developed. The results also show that the quality assessment by the reporting schemes is inconsistent and that it is not possible to distil the reporting type from a company report. The results add to prior literature by giving insight into the internal factors underlying sustainability reporting, and how these factors interrelate. They imply that inclusion of internal organisational factors in sustainability reports will be valuable information to their users.