You want to know more about the selecting the jurisdiction to collect sales tax.
Your business activities determine your jurisdictions. Each state defines the rules for when a business is required to collect and remit sales and use tax. If sales occur in jurisdictions you have not selected in AvaTax, the resulting tax calculation returns a value of zero tax. In this step, you'll tell AvaTax where your company is registered to collect and remit sales tax.
For more information about nexus, read Add Nexus Jurisdictions.