Welcome to the Vertex® Developer Network. The Vertex REST APIs for O Series give you access to high quality tax calculations, synchronization, configuration, and tax area lookup. Depending on the access key that you are using, you can securely calculate taxes against your own environments using commonly available API development and testing tools.

Continue reading to learn all about our APIs and the developer tools available here in the Vertex Developer Network or see our Quick Start Guide to jump right into integrating your financial systems with O Series.

O Series APIs

Vertex currently provides REST v2 APIs for the following web services:

• Get Started with Calculation and Transaction Management - Calculate tax from the buyer's, owner's, or seller's perspective. Manage transactions between Vertex O Series and your host system.
• Get Started with Tax Area Lookups - Retrieve tax area information using multiple criteria such as postal
  address or latitude/longitude coordinates.
• Get Started with Tax Configuration - Create, retrieve, update, and delete O Series tax configurations
• Get Started with User and Role Management - Efficiently manage user access in O Series On-Premise and On-Demand, ensuring that your team members have the appropriate permissions to perform their tasks.

O Series OAS files

Use these links to download the OpenAPI Specification (OAS) file for the O Series APIs.