The paper examines various rationales for applying equality and human rights proofing mechanisms to fiscal policy. The principle of using available resources to the maximum to progressively realise human rights, and not to erode the revenue capacity of developing nations to do likewise, is at the heart of emerging human rights norms. To date, Irish budgetary processes and major policy statements such as the Commission on Taxation or the draft outline National Plan on Business and Human Rights Strategy have not engaged with the principles of maximising available resources or extraterritoriality. Proofing fiscal policy is also relevant from the perspective of fiscal welfare where taxation instruments, traditionally used as a revenue-gathering mechanism, are increasingly used as distributional mechanisms to achieve policy outcomes in pensions, health, housing and employment, with important equality and distributive dimensions, particularly from gender, age and socioeconomic perspectives. A number of practical institutional mechanisms and evaluative questions can guide equality and human rights proofing of fiscal policy, but commitments to maximise resources to realise rights also need to be promoted through a public discourse which sees taxation as potential investment in society rather than a burden or cost on the economy.