For the last decade a major trend within tax administrations has been to shift from a roughly one size fits all approach—where close to all taxpayers experience a deterrence approach—to a more responsive and collaborative approach as in co-operative compliance programmes. Such programmes build on the idea that the participating corporations disclose relevant information including their tax risks and are transparent to the tax administrations and in return will tax administrations provide real-time predictability and clarity concerning taxation issues of relevance for the corporation. In brief, co-operative compliance builds on the slogan: “…certainty in exchange for transparency” (OECD 2016, 7). Co-operative compliance has increasingly become a core concern and way of organizing the relation between tax authorities and large corporate tax payers when it comes to securing tax compliance. This working paper is the result of research by Work Package 6 in EU’s Horizon 2020 funded programme FairTax that has been running for the four-year period 2015-2019. Our research in Work Package 6 addresses how proactive engagements with large corporate taxpayers have affected regulation of tax collection and administrative processes, changed relationships between stakeholders and tax administrations, and influenced tax compliance in the Nordic countries. The aim of this working paper is to provide a comparison of the experiences in four of the Nordic countries: Denmark, Finland, Norway and Sweden and to propose recommendations. The Nordic countries are considered similar and so were the co-operative compliance programmes that were implemented in each country, yet the outcomes were very different. We thus dealt with various case characteristics (Flyvbjerg 2006) where the outcomes hinged on a complexity of elements. We argue that the Swedish case is an extreme case due to its turbulent life and concomitantly with only a handful of participants that have very little activity. The Norwegian case, in contrast, is an example of a maximum variation case because of the much longer history of collaborative relationships and the outcome of the work with tax risk. The combination of a collaborative way of working and systematic risk management and monitoring may either reflect a most likely scenario of future tax administration—or perhaps the least likely. Lastly, we argue that the Danish and Finnish cases represent paradigmatic cases because both of these align largely with the standards set by the OECD and because they therefore present more ordinary or regular ways of working with co-operative compliance. Analyzing a wide variety of case characteristics means that our findings can be of general interest, beyond the Nordic countries.