During the onboarding process, Avalara creates a Customer Portal account, which includes your Communications REST v2 account. If you don’t have a Customer Portal account, contact your Customer Account Manager to obtain a Customer Portal Username and Client ID.
When Avalara creates the Customer Portal account, you are sent an AvaTax for Communications (AFC) Portal Account Activation email with a link to activate your Customer Portal account. Follow the instructions in the email and you are all set! The Customer Portal password is the same password you use for REST v2 authentication.
Customer Portal Accounts are created in two environments: Sandbox and Production. To ensure that your API credentials are unique for Sandbox and Production, you must provide a different email address for each environment. This helps to prevent accidentally committing test data to your Production environment.
The AvaTax for Communications (AFC) Portal Account Activation email is sent from each environment. When you set your password, note which environment you are working in so you can avoid any password problems.