fatalEN 16931EN 16931 business ruleCIIUBLBG-20BT-97BT-98
Each Document level allowance (BG-20) shall contain a Document level allowance reason (BT-97) or a Document level allowance reason code (BT-98), or both.
A document level allowance (BG-20) has neither a reason text (BT-97) nor a reason code (BT-98).
Add a reason. A free-text BT-97 such as 'Volume discount' is enough and is the safer choice; add BT-98 (UNTDID 5189, e.g. 95 = Discount) only if you are sure the code matches the text - see BR-CO-05.
CII — context $Document_level_allowances
(../ram:Reason) or (../ram:ReasonCode)
UBL — context cac:AllowanceCharge[cbc:ChargeIndicator = false()]
exists(cbc:AllowanceChargeReason) or exists(cbc:AllowanceChargeReasonCode)
Nothing is stored, and the whole invoice is checked, not just this rule. A PDF only works if it is Factur-X / ZUGFeRD — a PDF with the invoice XML inside it.