Why is Netsuite sending my items over as non-taxable even though they are not mapped to a tax code?

Overview

My transactions have line items that show NT in admin console. However they are not mapped to the tax code NT, not mapped to a tax code at all, or are mapped to a different tax code

Environment

Netsuite

Resolution

• If the "Default TaxCode To" in the Avalara configuration (Tax Calculation tab) is blank. Ensure it's set to 'New and Existing Customer(s)'.
• This can happen if your item also happens to be mapped as a Tax Schedule
  • Check Setup > Accounting > Tax Schedules
• If your item is also mapped here as a product and it's set to be non-taxable for nexus in a specific state, Netsuite will override your item mapping and send AvaTax  "NT" for the item/product in the specified state.