In recent years aggressive tax strategies lead to a new phenomenon denominated by the OECD as ‘base erosion and profit shifting’ (Beps). The OECD and G20 countries adopted in 2013-15 a 15-point Action Plan to address Beps (the ‘Beps Project’). In respect to tax treaties the OECD adopted in 2016 a Multilateral Instrument and in 2017 issued a new release the Commentary to the OECD Model Tax Convention on Income and on Capital. These changes were approved as part of the Beps Project in Actions 2, 6, 7 and 14. The article describes the Model/Commentary 2017 and looks at the impact of the OECD Beps Pproject on tax treaties in terms of PE access, entitlement and investment protection The article focuses on three main dimensions for a resident of a Contracting State of doing business in the other Contracting State: first, the tests required for doing business through PE (section 2); second, the new set of requirements that need to be met to have full entitlement to the tax treaty (section 3); third, the basic rules for doing business through a corporate vehicle, once the entitlement requirements have been met (section 4). The article concludes with the discussion of tax treaty dispute settlement and enforcement by looking at the mutual agreement procedure, transfer price allocations in tax treaties, and tax treaties and information (section 5).