Tax code error in Enter valid tax code in invoice collaboration

Hi all, We are using invoice collaboration and want supplier to create invoices in SNC. We have maintained the tax code in "Maintain tax code for invoices" in SPRO for the customer and supplier combination. But we are getting the below error when try to create invoice by supplier login. Invoice &1, item1: Enter valid tax code. / SCA/DM_Invoice 068 - error Tax value for sales tax I0 item 1 could not be determined /SCA/DM_Invoice 006 - warning The vendor is non ERS vendor and the PO does appear in Due list of invoice documents. Can you let us know if we missing any config? thanks, mahesh matekar.