How PostalCodes.info builds and validates postal code datasets

This methodology note explains how PostalCodes.info normalizes country, region, and locality data; validates live URLs; limits sitemap inclusion to healthy records; and keeps reusable datasets aligned with search demand and canonical behavior.

PostalCodes.info maintains postal-code reference data for search, data, and developer use cases. The note documents quality checks, source alignment, API and dataset outputs, and the operational rules used to avoid stale or duplicate postal-code pages.

Main site: https://postalcodes.info/
Datasets: https://postalcodes.info/datasets
API: https://postalcodes.info/api