invitbox allows you to import your tax rates from Saasu and choose defaults for taxable and non-taxable items.
Managing your Tax Rates and setting defaults
Invitbox allows you to choose which of your Saasu tax rates to act as the default. What this means is that if invitbox detects that an item is taxable or non-taxable, it will use these defaults to send with the bill line-data to Saasu unless you choose to assign other non-default tax rates to the item. For further information on assigning non-default tax rates to a bill, see here
You can manage which tax rates are the defaults via Admin > Tax Rates > edit.