There now exists a substantial volume of empirical evidence which has examined the superiority of the ‘M’‐form organizational structure for the management of large, diversified enterprises. Regrettably, attention has mainly been focused on manufacturing companies, despite the rising importance of the service sector in most major economies. This paper examines organizational structures within one segment of the UK service sector: the insurance industry. In the UK this industry has undergone significant, regulatory‐driven structural change and, as a consequence, the majority of companies have undertaken organizational change. The results produced, however, suggest that many of these companies adopted sub‐optimal divisionalized structures.