In Customization > General settings you can now add taxes to orders on checkout. When this feature is enabled, taxes will be taken into account / calculated for all the products / items in the cart.
Please note that taxes are applied to goods' value, to shipping, to Extra Offers (pre-sells) if the trigger is set to "Active" state.
Set the appropriate trigger to 'active' state in order to add Tax/VAT charge to orders
Once this option is active, you can visit "Shipping" and "Extra offers" sections and decide whether tax collection should also be applied to rates and to additional paid options (pre-sells).
Example: No tax is added to shipping rate on the checkout
Example: Tax is added to this extra offer
Taxes (VAT rates) are calculated automatically based on the data available in this library: https://taxsummaries.pwc.com/quick-charts/value-added-tax-vat-rates
The tax rate will be calculated also for the USA, state by state. We used the data found in this source for the rates.