Fetch Country List API: Building Dynamic Registration Forms
Learn how to use country reference data in registration forms, organize administrative selections, and handle location data with an API.
October 24, 2026 3 min
Blog
Guides, explainers and references on addresses, postal codes and country data for developers.
World States and Cities List: Developer Integration Guide
Learn how to integrate country, state, and city reference data into your application for geographic dropdowns and address-related form workflows.
October 21, 2026 2 min
Postal Code Format Validation: A Developer Implementation Guide
Learn how to check postal code formats in web forms with country-specific regex rules and administrative reference data.
October 18, 2026 2 min
ISO 3166 Numeric Codes: A Practical Guide for Software
Learn what ISO 3166-1 numeric codes represent and how to handle them in software and databases.
October 15, 2026 2 min
Checkout Address Validation API: Catch Address Issues Earlier
Learn how address validation and autocomplete can help identify address data issues during checkout and support a more reliable e-commerce shipping workflow.
October 12, 2026 3 min
How to Integrate an Address API Into Your Software Application
A practical guide to integrating an address API, covering backend proxying, autocomplete, administrative location data, and reliable error handling.
October 9, 2026 3 min
ISO 3166-1 Alpha-2 Codes: A Developer Overview
Learn what ISO 3166-1 alpha-2 codes represent, how they relate to other parts of ISO 3166, and where they are used.
October 6, 2026 2 min
Postal Code Validation API: A Practical Implementation Guide
Learn how to handle country-specific postal code formats in address forms, normalize user input, and use postal code lookup data.
October 3, 2026 3 min
Address Autocomplete API: Integrating Location Data in Forms
Learn how an address autocomplete API can help simplify form entry, and how administrative location data supports postal code lookup and validation.
October 2, 2026 3 min