• non financial disclosure
• assurance
• business model

Research objectives. The primary objective of this research is to propose a tool to assess the materiality of non-financial information (NFI). In fact, given the subjective nature of NFI, also materiality is subjective for each company, entailing the need for a tool that could be generally applicable. In this research, the Business Model (BM) emerges as a tool to overcome these limitations.
Research design. The research intends to simulate how to operationalize the proposed assurance process through a content analysis procedure. In addition, through a practical application of that process to a population of British companies listed in the EuroStoxx600, the research aims to understand if companies’ disclosures are currently consistent with the BM. Additionally, a regression analysis studies the determinants of disclosure consistency. Then, the assurance statements of the same companies are analyzed to understand what auditors currently focus on when performing their assurance tasks. Through a regression analysis, factors influencing assurance statements’ depth are studied.
Results and practical implications. From an operational point of view, the framework identified can be helpful for auditors in conducting the assurance process and for companies in organizing their disclosure. Results show that, at the time being, only half of the pieces of information disclosed are consistent with the BM, and auditors have standardized processes and opinions for NFI assurance. The auditors’ dependency on the client and the possible presence of managerial capture suggest the need for more research on this field.
Originality: Currently, few pieces of research on non-financial assurance exist, and most of them are focused on the presence of information rather than its relevance or on sustainability reports only. The present study aims to overcome these limitations by providing a tool to assess the materiality and consistency of this type of information and providing a practical example of how to use the developed framework.