Postal data snapshot retrieved 2026-10-18.

DE, AT, HU, ES, PL, IT, TR, PT, HR: GeoNames postal data. https://download.geonames.org/export/zip/
Creative Commons Attribution 4.0: https://creativecommons.org/licenses/by/4.0/
Transformed to postcode → place-name arrays; coordinates and account data are not included.

GR: © European Union - GISCO, 2024, postal code point dataset, Licence CC-BY-SA 4.0.
2025 distribution: https://gisco-services.ec.europa.eu/distribution/v2/pcode/csv/PCODE_PT_2025_4326.csv
https://ec.europa.eu/eurostat/web/gisco/geodata/administrative-units/postal-codes
https://creativecommons.org/licenses/by-sa/4.0/
The derived GR postcode list remains available under CC BY-SA 4.0.
Changes: selected CNTR_ID EL, retained unique POSTCODE values, removed spaces and other columns.
Non-geographic and some newer postcodes may be absent. GR has no verified shipping-city mapping in this dataset.
No affiliation or endorsement by the source providers.

PL: snapshot PL.zip retrieved 2026-10-18; normalized NN-NNN keys to five digits, preserved original place names. Customer-facing postal codes retain NN-NNN formatting.

IT: snapshot IT.zip retrieved 2026-10-18; retained five-digit CAP including leading zeros and original place names. Unknown postal codes or city mismatches remain advisory only.

TR/PT/HR: snapshots retrieved 2026-10-18. PT NNNN-NNN normalized to seven digits and displayed with a hyphen. Municipality names included for PT; province/district aliases included for TR. Lookup misses remain advisory.

DK: GeoNames DK.zip snapshot retrieved 2026-10-18; four-digit postcodes and original place names retained. Unknown postcodes and city mismatches remain advisory. SHA256: 6f45abde74275e089c4874afb6f1e8ed8fd852fc3191230442fb38b75afec818.

US: GeoNames US.zip snapshot retrieved 2026-10-18, CC BY 4.0. 41,488 five-digit ZIP keys, city names and state abbreviations. ZIP+4 uses the five-digit prefix for advisory lookup only; format and state selection are validated separately. SHA256: cc4623312950e92fe72b7b666dac58f1e74bb8ee91c3271fbb8e1b20aa40a0e2.