This paper discusses Tax strategy assessment with a focus on various operating models that are available to enhance the Tax function from a sourcing perspective. Are tax activities being performed internally or externally through the use of a third party? Why would Tax consider a change in approach and what are the drivers in assessing which sourcing method provides the best strategic fit? In this paper, we also address how ongoing technology disruption in the marketplace influences key Tax sourcing decisions. Finally, we will explain how to get started on a path to the most effective sourcing model for success.