When trying to post cost invoice in invoice approval journal where are two project type of lines (credit and debit) and two different sales tax codes used (VAT25,5 and VAT0). Only the amount of VAT will be paid for the vendor. Posting will end up in error: Tax direction must be specified on ledger account . No specific ledger account is mentioned in the warning. VS debugger shows that validation try to find sales tax direction for "empty" ledger account. Posting will passthrough when GL Sales Tax parameter Tax direction requirement is switched off. All needed ledger accounts have tax direction. SingUp Software's ExFlow AP automation is used. Posting of approval journal is standard functionality. Tax direction validation in this case was working in version 10.0.36 but not anymore.