# Exemptions in AvaTax

Source: https://developer.avalara.com/ecommerce-integration-guide/transactions/exemptions/exemptions-in-avatax/

An exemption refers to the reason that certain transactions that don't get taxed. To understand exemptions, you’ll need to understand the following:

-   What are the factors that could cause the tax on a transaction to be zero?

-   How do I set up exemption certificates for customer exemptions?

-   How do I use exemption numbers to exempt transactions?

-   How do I define entity use codes to exempt entire transactions or lines on a transaction?

The sections that follow describe each of the above items in greater detail.