AddressZen
7.9#2 in address verification software$49 one-timeFree planAndroidiOSWebAPI
VisitAddressZen vs UPU POST*CODE API
UPU POST*CODE API
6.0#23 in address verification softwareWebAPI
VisitWhat both publish
| Fact | AddressZen | UPU POST*CODE API |
|---|---|---|
| Documentation | Documentation includes integration guides, API reference, SDK instructions, key management, testing, data coverage and changelog material. | The API documentation includes tutorials, quick-start guides, and developer tooling. |
| Founded | 2012 | 1874 |
| Integrations | Listed integrations include Zapier, Adobe Commerce, WooCommerce, Contact Form 7, Gravity Forms, Gutenberg, Ninja Forms, FormAssembly, Formidable Forms, Formstack, JetFormBuilder and Elementor Pro. | The API can be used as a CDS plugin, through the CDS API gateway or other middleware, or integrated into postal websites and local applications. |
| Security | AddressZen says its information security management system was recertified to ISO 27001 in 2025 and that its certification streak began in 2020. | The CDS setup guide describes a security token used to identify and authenticate a CDS installation, with tokens unique to countries. |
AddressZen plans
- FreeFree
- Free for 1 yearFree
- 1,400 verified addresses$49, paid once
- 5,000 verified addresses$149, paid once
- 14,000 verified addresses$349, paid once
- 55,000 verified addresses$1,000, paid once
UPU POST*CODE API plans
- Contact UPU for pricingPriced on request
Pick AddressZen if…
AddressZen suits businesses and developers that need to validate, standardize, or suggest US and international addresses. Its API and integrations may fit websites and forms that collect address details.
Pick UPU POST*CODE API if…
The API suits postal operators, businesses, and individuals who handle international addresses. It can support address capture in web shops, customs declarations, user platforms, and ERP systems.