When using Supplier Invoice Create to create invoices for which AvaTax will calculate tax, the same restriction applies regarding the Tax Excluded field as applies for customer invoices. If you do not select the Tax Excluded field, an error message displays when you try to save the invoice.

When creating a supplier invoice, if you update the ship-to record in the Addresses tab to a different business relation address not linked to the current supplier, AvaTax returns tax details based on the new, unlinked ship-to address.