The COVID-19 Infection Survey (CIS) was launched in England in mid-April 2020. Working with the University of Oxford, University of Manchester, UK Health Security Agency, Wellcome Trust, IQVIA and the Lighthouse Laboratories at the UK Biocentre Milton Keynes and Glasgow, its aim is to provide information on how many people across the UK have COVID-19 infection at a given point in time, either with or without symptoms and how many are ever likely to have had the infection. This dataset contains information on mortality, taken from the national Deaths Registration data for England and Wales, for CIS participants only. Deaths information includes date and registered cause(s) of death, attached to CIS IDs. Mortality data have been linked to CIS ID via NHS (National Health Service) number, as derived from the linkage of CIS to the Personal Demographic Service (PDS). CIS IDs in this file will enable users to attach the mortality data to CIS attributes data, which is also available in the SRS for researchers to access. This dataset is subject to caveats around the quality of the linkage of CIS to PDS, and there may be small numbers of false positive links or missed links in the dataset.