In May 1843, around two-fifths of the clergy of the Church of Scotland resigned in protest over the ‘intrusion’ of the state in matters relating to ecclesiastical governance. The greatest single challenge facing the newly established Free Church of Scotland was financial: how to pay the stipends of its ministers. The solution was the Sustentation Fund, the aim of which was to guarantee a minimum stipend for all ministers by redistributing funds raised. This article describes and analyses the development of the Sustentation Fund, highlighting its critical role in financially cross-subsidizing congregations in peripheral rural areas. In analysing the direction and scale of cross subsidy, the results throw new light on two questions. First, the extent to which, across geographical location and time, rural congregations were dependent on urban cross subsidies. Second, the geographical location and financial commitment across time, of the church’s urban, net contributor, congregations.