This article argues, using evidence from Georgian London, that historical demographers need to revisit the effects of two inter-related phenomena: the effects of burial fees on interment practices and the ebb and flow of a very considerable ‘traffic in corpses’. By the eighteenth century burial space in London was at a premium and there was an active market in the provision of suitable, and affordable, burial grounds. This article is based on the sextons' books of the Westminster parish of St Martin in the Fields. These books are very unusual in recording exported ‘certificate’ and ‘arrears’ burials. The ‘traffic in corpses’ revealed by this source is analysed in some detail and burial fees turn out to be of great importance in understanding local fluctuations in interment practices. A neighbouring parish, St Anne, Soho, was acting as a veritable ‘clandestine burial centre’ which interred non-parishioners for profit on a huge scale for most of the eighteenth century. The ‘commodification’ of burial, driven partly by considerations of cost, thus had a major impact on interment practices in the eighteenth-century metropolis. A key finding is that, due to this postmortem flow of corpses, the total number of recorded burials in any one parish may not necessarily have been driven by fluctuations in local mortality rates.