GeoPostcodes is a commercial provider of worldwide postal code and administrative boundary databases. People searching for it are usually evaluating data for an application or comparing it with free sources. ZIPCodeLookup.io is not affiliated with GeoPostcodes.
What licensed postal data adds
Commercial datasets typically offer global coverage in one schema, regular updates, boundary polygons, multilingual place names and support. If you ship to many countries or need boundaries rather than points, that is the kind of product to evaluate; see geopostcodes.com for its current offering.
What free data covers
For U.S. five-digit lookups, the GeoNames postal dataset used by this site gives place, state, county association and a representative coordinate under an attribution license. It has no boundaries, no ZIP+4 and no address-level detail. Our data sources page spells out the limits.
Choosing
Prototype with free data, measure what your application really needs (boundaries, updates, other countries, address verification), then license only the pieces that matter. The ZIP code lookup API guide covers the integration side.