This data resource provides plot-level plant occurrence data for the first three years (2015-2017) of the National Plant Monitoring Scheme (covering the UK, the Channel Islands, and the Isle of Man). Data consist of individual observations of plants, and other habitat characteristics, at the metre-scale; observations are accompanied by percentage cover information recorded according to the Domin frequency-abundance scale commonly used in plant community ecology. Other information provided includes the plot type (size, shape, according to the NPMS classification), the volunteer-recorded NPMS habitat, the date of sampling, and information regarding the spatial location of the plot. Information contained within the metadata file should allow users to reconstruct the sampling history (including gaps) of any plot that has been sampled within the NPMS scheme between 2015 and 2017. Please be aware that this dataset is updated annually and that more recent versions exist. Full details about this dataset can be found at https://doi.org/10.5285/890e4d3d-ae93-4528-8e88-bc01bae3907b