Commerce VAT introduces the concept of Place of Supply which is commonly used by countries implementing VAT. A Place of Supply rule is created for each active country. If the conditions pass a rule is called to calculate the rate to be applied from that countries rates.
Each rate can now have multiple rate each with a start date. This allows a "Standard" Rate to be defined but within that have 19% that started on 1st Jan 2000 and 20% that will start on 1st Jan 2020, the change in % calculation will be automatic based on the order date when rules calculates the "Standard" rate.
A rules action is included to calculate the highest rate of tax on an invoice. This can then be used to apply the correct VAT rate to shipping. A default rule is included
