Nomad (NOPS) has two ways to handle sales tax calculations – Destination Tax and Avalara AvaTax

Are you using:

Destination Tax - The premise is that a destination usually dictates a tax rate. If a tax code is not defined for a specific location then it will use the default tax code. All logic only applies if the customer is taxable. Avalara Tax - Nomad integrates with Avalara’s AvaTax system to provide a mechanism for tax estimation without the need for configuring a native destination tax module in your storefront.