Prior research shows taxpayers’ perceptions of fairness leads to greater cooperation and compliance with tax authorities. Yet our understanding of tax fairness has been hampered by its general reliance upon models and measures of fairness developed by organizational fairness research, even though fairness is a perception subject to contextual influences. Accordingly, we attempt to gain insight into the influence of contextual factors on fairness through the development of a theoretically based and empirically derived model of tax fairness, grounded in organizational literature, but empirically tested in the tax context. Our analysis shows the extent to which items and dimensions found in the organizational fairness literature reflect taxpayers’ perceptions of tax fairness. Most importantly, our findings contribute to fairness research by identifying the role of relevant comparison groups in affecting perceptions of fairness, and thereby extends our understanding of the role of context in affecting fairness perceptions. Furthermore, by identifying the dimensions and items incorporated in perceptions of tax fairness, our study provides a foundation for tax researchers and policy makers to determine how best to promote voluntary taxpayers’ compliance and in so doing, mitigate tax avoidance and tax evasion.