How do tax advisors make themselves comfortable with the tax planning arrangements they recommend to their clients, in the many gray areas that characterize their field of practice? What motivates tax advisors to consult each other in this context? In this field study, we examine the processes that help (re)produce an influential informal norm of peer consultation surrounding the work of tax partners in accounting firms. Based on interviews with 36 tax advisors, most of them partners in accounting firms, our analysis focuses on rationalization processes surrounding the informal consultation norm. Our findings shed light on partners' heavy reliance on this norm, to comfort themselves in exercising interpretive judgment about the meaning of tax rules. Clan monitoring and mutual support both play a significant role in the process. As such, our study illustrates how peer consultation operates as an interpretive practice socially embedded in clan processes. Partners negotiate the shared meaning of the law through clan-based interactions with their peers until a consensus is reached: the tax planning arrangement is then perceived to be robust enough and able to withstand external challenges. Overall, our analysis points to a need to step back from the current tax avoidance debate, to better understand how clan-based interpretive judgments develop and operate in practice, in their social context. We also hope to influence the discipline’s research agenda by encouraging academics to seek a better understanding of tax planning in action.