Bioenergy with Carbon Capture and Storage (BECCS) is a carbon reduction technology that offers permanent net removal of carbon dioxide (CO2) from the atmosphere. This has been termed 'negative carbon dioxide emissions', and offers a significant advantage over other mitigation alternatives, which only decrease the amount of emissions to the atmosphere. The benefits inherent within this technology are currently receiving increased attention from policy makers. To facilitate the development of appropriate policy incentives, this paper reviews the treatment of 'negative carbon dioxide emissions' under current and planned international carbon accounting frameworks. It finds that, while current frameworks provide limited guidance, proposed and revised guidelines could provide an environmentally sound reporting framework for BECCS. However, the paper also notes that, as they currently stand, new guidelines do not tackle a critical issue that has implications for all biomass energy systems, namely the overall carbon footprint of biomass production and use. It recommends that, to the best extent possible, all carbon impacts of BECCS are fully reflected in carbon reporting and accounting systems under the UNFCCC and Kyoto Protocol.