BR-27: Item net price cannot be negative
Item net price cannot be negative; use a nonnegative item net price and the appropriate credit-note or quantity convention.
What the rule says
[BR-27]-The Item net price (BT-146) shall NOT be negative.
Official en16931 source, version 1.3.16. EUPL 1.2; sources, licences and notices. Syntax and business checks are separate; this is not certification.
Item net price cannot be negative
Item net price cannot be negative. The controlled example changes the specific field or group named by this rule. Set only /*/cac:InvoiceLine[1]/cac:Price/cbc:PriceAmount to '-1.00'.
Business terms: BT-146.
Use a nonnegative item net price and the appropriate credit-note or quantity convention.
Reproduced failure and correction
Tested on 2 November 2026 with the production SaxonC-HE 13.1 / saxonche 13.1.1 engine, en16931 mode, UBL. The XSD passes; the report then contains BR-27. Restoring this fragment makes the complete original invoice pass the selected checks.
[BR-27]-The Item net price (BT-146) shall NOT be negative.Additional triggered rules: 0. None. Counts include distinct error and warning codes; the target code is excluded.
Precise mutated XPath: /*/cac:InvoiceLine[1]/cac:Price/cbc:PriceAmount.
Before: triggers this rule
<cac:Price xmlns:cac="urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2" xmlns:ubl="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2" xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2">
<cbc:PriceAmount currencyID="EUR">-1.00</cbc:PriceAmount>
</cac:Price>
After: passes
<cac:Price xmlns:cac="urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2" xmlns:ubl="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2" xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2">
<cbc:PriceAmount currencyID="EUR">100.00</cbc:PriceAmount>
</cac:Price>
The context shown is part of a complete invoice; it is not a standalone invoice. Mutation: value at /*/cac:InvoiceLine[1]/cac:Price/cbc:PriceAmount. The passing baseline is validated with the selected pinned package. UBL examples use a controlled single-line adaptation of the official XRechnung example; the CII example uses the official EN 16931 baseline.
Download complete failing invoice · Download complete passing invoice
Check the rest of the invoice
Repair the source data and exporter, then validate the complete invoice again with the same package. Review every remaining error and warning; a passing rule is not a guarantee of recipient acceptance.
EN 16931 syntax and business checks · XRechnung profile requirements · Pro/Team batch checks.