Many post offices in the UK have been or are in the process of being closed. The process of deciding which post office to close has been criticised for a lack of transparency and evidence. This work analysed the impact of proposed post office closures in an English county against national access criteria. Only one of five access criteria were satisfied by current proposals. An optimisation model was then used to identify alternative sets of post offices to close by minimising the ‘losers’ in terms of increased access distance for a) the whole population b) limiting long-term illness, and c) full time carers. Combining a GIS-based network analysis with an optimisation model was shown be an appropriate method to minimise the numbers of targeted groups who experience a decline in post office accessibility. As national targets will result locally in ‘winners and ‘losers’, the method is a tool for generating evidence in support of policy, it allows sub-national analyses (e.g. at a local authority level) of the impacts of closures and can identify alternative closures better suited to local priorities.