> For the complete documentation index, see [llms.txt](https://docs.prestashop-project.org/1-6-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.prestashop-project.org/1-6-documentation/english-documentation/user-guide/making-the-native-modules-work/billing-and-invoicing-modules.md).

# Billing & Invoicing modules

## Avalara - AvaTax <a href="#billing-and-invoicingmodules-avalara-avatax" id="billing-and-invoicingmodules-avalara-avatax"></a>

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.

## European VAT Number <a href="#billing-and-invoicingmodules-europeanvatnumber" id="billing-and-invoicingmodules-europeanvatnumber"></a>

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:

* **Your country**. Choose your shop's country.
* **Enable checking of the VAT number with the WebService**. Tell PrestaShop that you want to retrieve the VAT for your country.

The VAT field appears only when the customer enters his or her company name in the address field.