We provide a critical reflection of Toms and Wilson's 'new paradigm of British business history' by focusing on the logical consistency of their model, the robustness of its predictive powers, and its explanation of transitional change related to stages of business capitalism. For example, central to the paradigm is the importance of accountability and external economies of scale, assumed as exogenous parameters in the analysis of British business history. This assumption is challenged, as is the predictive powers of the analytical matrix in providing an all-encompassing model for British business evolution. In particular, the transitional processes in British business history are not simply reducible to an assessment of accountability and economies of scale and scope, but rather to enhance our understanding there is a need also to engage with the concept of personal capitalism. While business historians should engage with theoretical frameworks, it must also be recognized that firms are idiosyncratic, a feature of business organizations that should not be lost.