The European Commission has presented a proposal to levy energy taxes on fuels sold to international shipping as part of the proposed revision of the Energy Taxation Directive (ETD). This report presents a number of case studies to assess the impact of the taxes on the European bunker market. The main conclusion is that European ports will not be able to offer competitive bunker prices compared to many ports non-EU ports and that there is a significant risk that bunkering activity will be relocated to non-EU ports. This means that the intended effect of the tax will not be achieved; shipping companies will be able to avoid paying taxes and the price of transport will not increase. There is no financial incentive to reduce fossil fuel use and avoid greenhouse gas emissions.