This study examines which organisations participate in cooperative compliance programmes(CCPs) and why by comparing large organisations in the Netherlands that do and do notparticipate in them. We use data from surveys conducted among representatives of largeorganisations and their Netherlands Tax and Customs Administration (NTCA) accountmanagers between 2014 and 2018 (n=394). The results show that there are few differences inorganisational characteristics between CCP participants and non-participants, but that largerorganisations are more likely to participate in CCPs. Furthermore, CCP participants have betterworking relationships with the NTCA, better Tax Control Frameworks (TCFs), and displaygreater transparency than non-participants. In addition, CCP participants report having agreater need for certainty and higher perceived certainty about their tax positions than nonparticipants.Within the group of CCP participants, we also assess whether there are differencesrelated to the intensity of contact with the NTCA and the duration of participation. We findthat the working relationship and the level of transparency are somewhat better, and thatcompliance costs for the organisation are reduced, when there is more frequent contact betweena large organisation and the NTCA. At the same time, we find a negative relationship betweenthe duration of CCP participation and the quality of the TCF. We conclude that largeorganisations may benefit from CCP participation in terms of gaining more certainty abouttheir tax position, whereas the tax authority may benefit because the organisation displaysgreater transparency. Both parties may benefit from the development of a better workingrelationship, but it appears that both parties need to continuously invest time and effort into theprogramme in order to actively maintain the cooperative relationship.