Defines the tax codes that are valid for a combination of tax classes on a particular date.
Only one tax code per tax rule can be applicable for a sales item, however multiple tax rules could apply to the same sales item.
The ‘priority’ and ‘sort order’ will allow us, in situations where more than one tax code applies, to vary which ones get applied first and whether they apply to the original value or are compounded as they are added.
The priority is set to an integer and indicates how the values are to be applied e.g. if there are three valid rules with priorities 1,1 and 2, the first two tax codes are calculated on the original value and added together. The third tax rate is applied to the result.
The sort order indicates which rule is applied first, second, third etc if more than one is valid.