This dataset contains samples and occurrences of insects and flowers collected for the 1 km square survey of the UK Pollinator Monitoring Scheme (PoMS). It covers the years 2017 to 2021 (note that 2017 was a pilot year and has less data than subsequent years, and that the survey first became active in Northern Ireland in 2021, which was a pilot year in that country). This survey uses pan-traps positioned on transects within a randomly allocated set of 1 km squares across the UK. The sample data contains information on the location of the traps, various environmental variables, and the total number of insect specimens collected. The occurrence data for insects contains records of all hoverflies and bees from the traps, identified (wherever possible) to species level. The occurrence data for flowers contains records of all forbs that are in flower within 2 metres of each pan-trap station. (In addition, Flower-Insect Timed Counts are carried out in the same 1 km squares, see separate dataset for these data.) UK PoMS is coordinated by UKCEH, with involvement from the following partners: Bumblebee Conservation Trust, Butterfly Conservation, British Trust for Ornithology, Buglife, Hymettus, Natural History Museum, the University of Reading and University of Leeds, and working with recording schemes and societies. UKPoMS is advised and supported by a Steering Group, involving UKCEH, JNCC, DAERA, Defra, NatureScot, Welsh Government, All-Ireland Pollinators Plan, and SASA. Full details about this dataset can be found at https://doi.org/10.5285/9df83130-e98f-48b0-bbfc-32f5920eedb0