This dataset includes records of insect pollinator and flower data from within a wide range of land use types across Wales, collected as part of the Environment and Rural Affairs Monitoring & Modelling Programme (ERAMMP) National Field Survey (NFS) between the summers of 2021-2023. Professional surveyors conducted transect surveys (counting pollinating insects) and timed observations (recording insect-flower interactions). Butterflies were recorded to species-level, and bees and hoverflies were recorded to functional group-level. Density of flowering plants on each transect section was recorded on a DAFOR-X scale. In total, 146 1 x 1 km grid squares in Wales were surveyed, with each visited twice in one year in either 2021 or 2023. ERAMMP NFS is a resurvey of all of the 300 locations from the initial Glastir Monitoring and Evaluation Programme (GMEP) monitoring program (300 1km squares) on a rolling annual basis, with the aim to resurvey all sites between 2021 and 2025. The initial monitoring program, GMEP, was set up by the Welsh Government in 2013 to report national trends and monitor the effects of the Glastir agri-environment scheme on the environment and ran from 2013 to 2016. The field survey element was based on a stratified random sampling design of 300 x 1km square sites across Wales, and was managed by the UK Centre for Ecology & Hydrology. Full details about this dataset can be found at https://doi.org/10.5285/1b90ebdc-3aa3-4832-8a3f-067494d8d218