tax_categorycan have many
tax_rates, which indicate the rate at which the products belonging to a specific tax category will be taxed at. A tax rate links a tax rate to a particular zone (see Addresses for more information about zones). When an order is placed in a specific zone, any of the products for that order which have a tax zone that matches the order's tax zone will be taxed.
Spree::Calculator. In most cases you should be able to use Spree's
DefaultTaxcalculator. It is suitable for both sales tax and price-inclusive tax scenarios. For more information, please read the Calculators guide.
Spree::Config[:tax_using_ship_address]setting) is changed for the order to outside this taxable zone, then the tax adjustment on the order will be removed. If the address is changed back, the tax rate will be applied once more.