A key perceived benefit from being a charity is the potential eligibility for a range of tax concessions. Exemption from income tax is a benefit that is directly applicable to accumulated income and potentially relevant to all charities. The United States, Canada, United Kingdom, Australia and New Zealand all condition the exemption upon the ongoing operation of an entity or application of its assets for its charitable purposes and some also limit the exemption for unrelated business income. The extent to which this requirement might preclude accumulation is therefore investigated in the first part of this chapter, focussing primarily on the Australian provisions and contrasting those in the United Kingdom. As quasi-wealth taxes, minimum distribution rules for philanthropic foundations (United States and Australia) and generally for charities (Canada), are also of broad significance for the accumulation of income and assets and are considered next. Finally, the chapter touches upon the recent US excise tax on university endowment income.