In Canada, we must charge sales tax - HST or GST - based on where we are supplying goods. Provinces in Canada have different tax rates. Currently, the tax rate assigned to a customer is used when an invoice is created. However, the ship to address should be used in order to determine which tax applies. Currently, we have to keep a chart handy and manually override the tax rates on each line item in order to make sure the correct tax is charged based on where the order is shipped. It would assist with compliance greatly if tax rates were charged based on the customer's ship to address.