The paper observes that the term ‘business model’ has been incorporated in recent financial reporting regulations. The first section of the paper describes various meanings of ‘business model’ and demonstrates that the term has no settled or agreed meaning. The second part of the paper considers the suitability of the term ‘business model’ as a basis for a measurement standard (IFRS 9) or for requirements for narrative reporting and concludes it is not suitable for either purpose. Examples from the UK FTSE 100 index companies are used to illustrate existing usage in narrative reporting, finding varying levels of informativeness of disclosures about business models. The final part of the paper discusses reasons for incorporating an ambiguous and contested term in reporting guidance. It identifies parallels with ambiguity in other branches of financial reporting and the potential utility of ambiguity in allowing consensus to be arrived at on a form of words, apparently tightening up reporting regulation, while allowing participants ‘wiggle room’.