Access to ‘universal banking services’ through the post office network has been a goal of the UK governments over the last twenty years. Various policies and mechanisms have been put in place in an attempt to maintain national geographical coverage with access points while increasing the financial viability of the network. One such mechanism is represented by the six official criteria for access to post offices, expressed as a percentage of the UK population living within one mile, three miles, and six miles of a post office. The method for calculating compliance with these access criteria is not published. Nor will any granular results be published, but only an annual statement that the criteria are being met. This article examines geographical and temporal access to post offices in order to understand the territorial coverage of the network and the impact this has on the provision of basic banking services. The area under investigation is Wales, for which we are reviewing the Government’s official access criteria. Through the Post Office Ltd website, we are collecting up-to-date information on the locations and opening hours of post offices in Wales. In addition, a detailed population grid is combined with calculated areas of equidistant geographical access, called isochrones, to determine the number of people who have access to the post office network. The isochrones are based on the Welsh road network and are calculated for different travel modes and thresholds using a powerful routing engine. Our results show that the official access criteria are largely unmet in Wales. In addition, and in contrast to previous studies, we show a rural-urban divide not in terms of spatial access, but in the combination of spatial and temporal access. The results are of both practical and theoretical value and will hopefully inform policy makers.