API Docs

Avalara provides automated sales tax solutions to streamline cumbersome, error-prone tax compliance processes and reduce the risk of loss or penalty in case of an audit. Our automated solutions perform address validation, jurisdiction research and rate calculation and allow you to manage even the most complicated tax issues, such as situs, nexus, tax tiers, tax holidays, exemptions, certificate management and product taxability rules.

We offer a number of different products to suit different compliance needs. This site is designed to describe the functionality of and best practices for our APIs. To use one of these APIs, some development work will need to be done to integrate to your webstore or accounting application.

You can find sample source projects for most languages from our API Sample Code page. We will continue to keep this page updated with support for more languages.

Avalara AvaTax

Based on transactional information and a preset tax profile reflecting your business needs, tax is calculated. Transactions can be recorded for reporting and tax filing. This product also includes our address validation service. We offer two different ways to integrate to our tax service: a RESTful API and a SOAP-based API. We have pre-built classes in PHP, Java, and .NET based upon our SOAP API, and documentation on making direct web service calls using the WSDL.

Avalara CertCapture

This product can be used as a stand-alone certificate management solution, or in conjunction with the Avalara AvaTax product. Avalara CertCapture delivers a complete on-line solution that empowers the State Tax Professional by digitizing all relevant information relating to your State Sales Tax Exemption and Resale certificates for easy access. Professional Tax Services are included to ensure the speed and accuracy of results, while advanced reporting options give you more information than ever on your Sales Tax Exemption exposure. A variety of API resources are available to automate interaction with customer and certificate records, as well as bulk data. More information about the CertCapture product is available at the CertCapture home page.