ClickToAddress - ClickToAddress offers APIs for address lookup and verification.
Smarty - Smarty provides address validation, autocomplete, geocoding and reverse geocoding services covering addresses in over 240+ countries.
Addressify - Addressify is an API that allows developers to implement address verification, validation and autocomplete for Australia in their apps.
Loqate - The Standard in Global Address Verification
Addressy - Addressy is address verification software that captures and verifies addresses on websites.
streetlayer - Free, international and secure address validation, autocomplete and geocode JSON API for developers and businesses - compatible with PHP, Python, and more.