BR-27: The Item net price shall NOT be negative

StandardEN 16931-1 (European e-invoicing semantic model)SeverityError: the invoice is rejectedSyntaxUBL, CIIBusiness terms

BT-146 Item net price

Applies toEvery EN 16931 invoice: XRechnung, ZUGFeRD 2.x / Factur-X (profiles EN 16931, EXTENDED, XRECHNUNG), Peppol BIS Billing 3.0, and national CIUS such as the Dutch NLCIUS or the Italian/Spanish profiles.

Official rule text

[BR-27] The Item net price (BT-146) shall NOT be negative.

Why this error occurs

The element or combination is not allowed in this context. The file contains something the standard forbids: an element that must not be repeated, a value that contradicts another field, or data that belongs to a different profile.

How to fix it

Remove the offending element or make the two fields consistent as described in the rule text. If your software adds the element automatically, check for a profile setting (e.g. "EN 16931" vs "EXTENDED") or an export option that suppresses it.

What the validator checks

Checked element (context):

UBL

cac:InvoiceLine | cac:CreditNoteLine

Test (XPath):

(cac:Price/cbc:PriceAmount) >= 0

CII

//ram:IncludedSupplyChainTradeLineItem

Test (XPath):

(ram:SpecifiedLineTradeAgreement/ram:NetPriceProductTradePrice/ram:ChargeAmount) >= 0

Check your invoice

Drop your XML or PDF on the validator and every failed rule is linked to its page here. Free, no account, the file is not stored.

Check your invoice →

Same check via API:

curl -F file=@invoice.xml https://einvoicechecker.com/v1/validate

Related rules

BR-26 Each Invoice line shall contain the Item net price
BR-01 Specification identifier (BT-24) is missing
BR-02 Invoice number (BT-1) is missing
BR-03 Invoice issue date (BT-2) is missing
BR-04 Invoice type code (BT-3) is missing
BR-05 Invoice currency code (BT-5) is missing
BR-06 Seller name (BT-27) is missing
BR-07 Buyer name (BT-44) is missing

Frequently asked questions

What does BR-27 mean?

BR-27 is a en 16931 core rule: The Item net price (BT-146) shall NOT be negative.

Will my invoice be rejected because of BR-27?

Yes. BR-27 is flagged "fatal"; validators (KoSIT, Peppol access points, the German ZRE/OZG-RE portals) reject the invoice until it is fixed.

Which formats does BR-27 apply to?

Every EN 16931 invoice: XRechnung, ZUGFeRD 2.x / Factur-X (profiles EN 16931, EXTENDED, XRECHNUNG), Peppol BIS Billing 3.0, and national CIUS such as the Dutch NLCIUS or the Italian/Spanish profiles. Syntax: UBL and CII.

Source: EN 16931-1:2017 schematron (CEN TC434, via Peppol BIS 3.0.20). Catalogue generated from the official schematron on 2026-10-14.