Charge POS Tax According to "Ship To" Address.

The POS system will use the taxes set up in the Admin -> Billing -> Sales Taxes -> General Sales Tax Info -> Sales Tax District For Walk-Ins section. You can set up separate tax groups per location (Admin -> Inventory -> Inventory Locations) so that orders made for different locations can use taxes for the respective area by visiting the Click To Add Or Update link next to the label Additional POS Tax Groups. 

If you'd like taxes applied based on the ship to address for orders, you'll need to create fulfillment orders (Income -> Orders -> Fulfillment Order). You can have sales taxes applied automatically based on the ship to address by checking the box labeled Auto Select Sales Tax From Ship To On Fulfillment and POS Orders. If taxes exist in the system for the city, state, county for the address, those will be applied to the order.

You can import sales taxes by going to Tools -> Import -> Sales Tax.

You can also use NolaPro's Avalara AvaTax integration to have Avalara handle charging the appropriate sales taxes for your invoices. Find out more about the NolaPro-Avalara integration by clicking this link.