I dont know for other places in the world but where I live we need one tax for country plus another tax for the state.
We cannot charge state tax when the billing address is outside the state.
We cannot charge country tax when the billing address is outside of the country.
The tax percentage precision is 3 decimals (9.975%)
So the items would each have 2 tax rates, each taxes total for each item must be shown in the invoice.