Tax certainty aims at the stabilization of expectations of both, taxpayers and governments. Improving tax payer service, easing cooperation channels and clarifying legal framework are strategies already in place to increase tax certainty, even though to different extent depending on the countries level of development. For the short run, concrete measures can be recommended through which international cooperation can contribute to strengthening tax certainty. These measures concern the establishment of enhanced engagement programs, the development of model legislation as a tool for the implementation of international rules and standards, the alignment of bilateral treaties and domestic legislation to international good practices, using the country-by-country-report as an indicator for the adequacy of tax payments and setting up investment incentives. In the long run, a radical change in the international tax scheme is suggested since, amongst others, the current rules do not match with the emerging digital economy. A unitary taxation system might be therefore the appropriate response even if the implementation on an international level is complex.