This paper describes the steps involved in the creation of a UK-wide population register, covering the adult population from the start of 1997 to the end of 2020. We argue how this set of ‘Linked Consumer Registers’ will be the nucleus of a data infrastructure for bespoke demographic analysis that we are currently developing. We further appraise the applicability and value of this data infrastructure for empirical work within the social sciences, particularly in the context of modelling residential mobility and unpacking the relationship between socio-economic inequalities across ethnic groups and vulnerability to COVID-19.