Interest in sustainability and its implications for business has increased steadily since the issue first became topical two decades ago. It is increasingly recognised that sustainability not only poses ethical issues but also has direct implications for economic performance. The development of the regulatory framework of markets, technical and organisational innovations, and new societal and consumer perceptions, have changed the business context and the determinants of corporate success. This has implications for the professions that support business, and sustainability management has generated demands for new information and adaptations of conventional accounting to support it. There has been substantial research on a range of issues of sustainability accounting, but less is understood of actual practices within companies and how these are developing over time. Answers are needed to questions such as ‘what is understood by sustainability accounting in business practice?’, ‘how is sustainability accounting carried out?’, ‘who within companies uses the information which is generated, and for what purposes?’, and ‘what expectations are there of future developments?’. The Institute of Chartered Accountants in England and Wales therefore supported this project to build on previous research on sustainability accounting which it has carried out or supported, by researching into the status of sustainability accounting in business in practice. Given the relative youth of the subject, an exploratory study was made of practice in 16 leading companies in the UK and Germany, with interviews being conducted with more than sixty managers and other staff involved to explore current practice. This report provides an opportunity to examine the processes involved in generating business information, as distinct from the outputs that these processes generate. It also throws some light on how some leading companies are dealing with the additional information needs required in order to manage the increasingly topical issue of sustainability. It also has further implications. As sustainability-relevant information is largely non-financial in content, it also represents a specific instance of a broader current trend. This is the expansion of the generation and use in business of non-financial information to supplement the traditional financial information flows, both for external audiences through narrative reporting and for internal managements through balanced scorecards and similar systems. As this report shows, designing and managing non-financial information flows in practice is frequently handled by non-accounting specialists, particularly when this is in a new area that has not yet been systematised. This can be interpreted in either of two ways. It could be seen as a potential threat to the position of accountants as the leading practitioners in managing business information processes; however it can alternatively be seen as an opportunity to improve the processes involved by systematising them and incorporating the types of checks and controls to ensure integrity that are usually taken for granted in conventional accounting information, but which may be much less frequent with more novel non-financial information. The exploratory nature of the research means that the results can be only indicative rather than definitive, but they suggest a wide variety of practice which is still developing rapidly, with a number of emerging trends becoming apparent. These include a tendency for sustainability accounting in a company to become more systematised over time, and an increasing need for sustainability-related information of the same quality and reliability as is expected of other business information, including financial. This suggests a number of areas where further research can support the accountancy profession in adapting to this new challenge, including the development of a framework for sustainability accounting, ways in which sustainability accounting can be institutionalized and linked with conventional accounting, and the further development of new sustainability accounting tools.