Source & attribution
Postal data comes from GeoNames, licensed under Creative Commons Attribution 4.0 (CC BY 4.0). GeoNames is an open gazetteer; we use its post code export and keep attribution and the license link on this page.
GB full post codes come fromOS Code-Point Open, licensed under theOpen Government Licence v3. Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Contains National Statistics data © Crown copyright and database right 2026. Code-Point Open covers Great Britain; Northern Ireland remains outcode-only.
Dutch full post codes come fromCBS “Kerncijfers per postcode” (PC6, 2025 v1), free to use with attribution:© CBS, © ESRI Nederland (postcode area geometry). The six-character code is plotted at the centroid of its postcode area.
Method & updates
We download the GeoNames post code export, deduplicate and normalize it, then build the lookup database. Each build records the source hash and row counts; the "updated" date reflects the snapshot.