This article reviews the costing records of the 'Grand Allies', of whom George Bowes was a founder member. It assesses the contribution of these records to our knowledge of the development of cost accounting during the Industrial Revolution. It commences with an examination of the costings in the Grand Allies' minute book, before looking for evidence of dissemination in George Bowes' estate papers. It finds a body of practice, devised by colliery viewers, which had become widespread comparatively early in the north-east and which may have influenced costing methods in other regions, as the influence of the north-eastern viewers spread outwards during the eighteenth and nineteenth centuries. The findings in the article support other growing evidence of purposeful cost accounting in pre-industrial Britain.