The British Geological Survey Geophysical Logs Database provides an index into downhole geophysical log data from onshore UK boreholes held by BGS within the National Geoscience Data Centre (NGDC). Geophysical log data may be used to understand stratigraphy, aid mapping work, assess resources like groundwater and quantify subsurface variability, so they are critical to many projects across the geoscience sector in the UK, including those which contribute towards net zero objectives such as the assessment of geothermal resources, storage of heat and waste materials, and the identification of mineral resources. The database includes hardcopy records (with digital scans) as well as digital wireline data in lis, las and dlis format. The data are linked to the Single Onshore Borehole Index and may be queried by borehole and spatial location. Hardcopy records are held in NGDC at BGS Keyworth. Some of the digital wireline data are in binary file formats, including .lis, .dlis, .tap and .tif (not an image format), which require specialist logging software to use. The database represents the combination of three historic databases which date from 1985 onwards, and the primary data were collected by different drilling companies and for different purposes, so the data have varying provenance and therefore quality. Not all data in the database are provided externally. Some data remain confidential, and because of the aggregate nature of the dataset, a small amount of the data are considered suspect and are not provided publicly. Significant collections within the database are: 1. Data acquired by the former National Coal Board and British Coal during their exploration for coal in the UK. Ownership of UK coal exploration data was transferred to the Coal Authority (now the Mining Remediation Authority) following privatisation of the UK coal industry, with British Geological Survey as custodian of the data. These data are in general publicly available; however, access to data within active mining licences is restricted in that it requires the consent of the mining licensee. The Coal Authority data archive includes digital data for some of the geophysical borehole logging. These are mainly in the form of original field tapes; however, also available are some data transcribed onto more modern media during BGS projects. 2. Data from onshore hydrocarbon wells regulated by the North Sea Transition Authority (NSTA; formerly known as DECC – Department of Energy and Climate Change and OGA – Oil and Gas Authority). These oil and gas wells deeply penetrate the crust (often over 1 km deep) under the UK mainland and are geographically widespread.