Lob.com vs VATlayer

Lob's US Address Verification API checks, standardizes, and CASS-certifies a US postal address in real time, returning delivery-point-validation flags, vacancy and building-type metadata, and a corrected/deliverable address in one JSON response. It's the same verification engine behind Lob's broader direct-mail automation platform (mail creation, printing, and USPS tracking), so a key created for one Lob product works across the rest. Authentication is a single API key sent as the HTTP Basic Auth username, with separate test and live keys so integrations can be built and tested before any usage is billed.

vatlayer checks whether an EU VAT registration number is currently valid and, where the member state's VIES service exposes it, returns the registered company name and address alongside real-time and historical VAT/EU-VAT rate lookups by country. It's one of the apilayer family of JSON micro-APIs, sharing that group's account and billing platform. Requests are plain HTTPS GET calls authenticated with an `access_key` query parameter — no headers or OAuth handshake required.