Isah origin
This value depends on the identification method chosen for Vendor '99999' as set on the Supply Chain tab for InvoiceMain.CustId in T_Customer (Own company identification method).:
Path
Invoice/SELLER/Seller identifier/Scheme identifier
XML label
ubl:Invoice/cac:AccountingSupplierParty/cac:Party/cac:PartyIdentification/cbc:ID@schemeID