The data in postcodes-2025-03.gpkg.xz is based on the following datasets:
- OpenUPRN 03/2025: https://osdatahub.os.uk/downloads/open/OpenUPRN
- NSUL 02/2025: https://geoportal.statistics.gov.uk/datasets/2b7d7565f4a44d6ea9cf1553d235d9bc/about
- Local Authority Districts 12/2023: https://www.data.gov.uk/dataset/288458f7-7789-47d0-80d4-ffdf746c6b75/local-authority-districts-december-2023-boundaries-uk-bfe