Sustainability accounting focuses on providing information about sustainability-related risks and opportunities. Systematic sustainability accounting allows consistency and comparability of sustainability indicators over time and among companies. This chapter develops a standardised three-dimensional sustainability accounting model that considers risk levels, opportunity levels, materiality levels and total threat levels. Moreover, a categorisation of potential sustainability indicators is presented. An extended and concrete model to lead sustainability accounting to the next level is outlined, but further work is needed. Whether internal and external stakeholders consider the information generated by the model as relevant and reliable, for example, is an empirical question and needs further investigation. This chapter provides the impetus and a framework for such further research.