Sales Tax is complicated. AvaTax makes it easy.
Doing sales tax right is simple with Avalara. They do all of the research and automate the process for you, ensuring that the system is up-to-date with the most recent sales tax and VAT rates and rules in every state and country, so you don't have to. As a cloud-based service, AvaTax eliminates ongoing maintenance and support. It provides you with a complete solution to manage your sales tax needs.
This module enables your customers to fill in their VAT number in their details. The VAT can be fetched through a web service, based on your country.
The configuration screen is therefore quite straightforward:
The VAT field appears only when the customer enters his or her company name in the address field.