errorbusinessEN 16931

BR-28:The Item gross price (BT-148) shall NOT be negative.

Fix: This requires user input to resolve. Provide the correct value for `cbc:BaseQuantity` (BT-148). Upload your invoice to fix this automatically.

The Item gross price (BT-148) shall NOT be negative.. Review the `cbc:BaseQuantity` element.

Severity
Fatal
Rule set
EN 16931
Country
All EU
Fix type
AUTO-FIX
Confidence
90%
Category
party_info

Engine Classification

Auto-fix by taking absolute value of negative gross price. BT-148 must be >= 0.

Confidence: 90% · Applied automatically in pipeline

What is BR-28?

BR-28 is a fatal validation rule defined in the EN 16931 specification. It validates the RegistrationName element under PartyName > Name or cac:PartyLegalEntity in the UBL invoice XML.

When this rule fires, the invoice is rejected by Peppol access points and never reaches the buyer.

Target path: XPath: /Invoice/cac:AccountingCustomerParty/cac:Party/cac:PartyName/cbc:Name or cac:PartyLegalEntity/cbc:RegistrationName

Why This Error Matters

Invoice rejected. Negative gross prices are mathematically invalid.

BR-28 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.

Invoice Navigator can automatically correct this error in your pipeline. The fix is applied with full audit evidence, so your compliance trail remains intact.

Validator Behavior

  • ·Causes invoice rejection
  • ·Error returned: BR-28
  • ·Specification: EN 16931

How to Fix It

1.

Add trading name

In PartyName/Name

2.

Or legal name

In PartyLegalEntity/RegistrationName

3.

Match records

Should match buyer master data

Before / After

Failing XML
<cac:Price>
  <cbc:BaseQuantity>-100.00</cbc:BaseQuantity>
</cac:Price>
Corrected XML
<cac:Price>
  <cbc:BaseQuantity>100.00</cbc:BaseQuantity>
</cac:Price>

Technical Reference

XPathXPath: /Invoice/cac:AccountingCustomerParty/cac:Party/cac:PartyName/cbc:Name or cac:PartyLegalEntity/cbc:RegistrationName
SpecEN 16931
StrategyAuto-fix by taking absolute value of negative gross price. BT-148 must be >= 0.

Code Example

<cac:AccountingCustomerParty>
  <cac:Party>
    <cac:PartyName>
      <cbc:Name>Customer Corp</cbc:Name>
    </cac:PartyName>
  </cac:Party>
</cac:AccountingCustomerParty>

Common Causes

  • ·Negative gross price entered in source system
  • ·Calculation error when applying surcharges
  • ·Base amount for allowance set incorrectly
  • ·Data corruption during system migration
  • ·Manual price override with wrong sign

Seeing this in production? The API handles BR-28 automatically. See the fix response →

Commonly Seen In

All invoicing software

Frequently Asked Questions

The buyer must have either a trading name or legal registration name.

This requires user input to resolve. Provide the correct value for `cbc:BaseQuantity` (BT-148). Invoice Navigator detects this error and prompts for the required business data before applying a safe fix.

Yes, BR-28 is a critical error that will cause invoice rejection. It must be fixed before submission to ensure your invoice is accepted by the recipient's system.

BR-28 requires specific business data to resolve. Invoice Navigator detects the error and guides you through providing the needed information, then applies the fix with full audit documentation.

BR-28 is commonly seen in exports from All invoicing software. These software packages sometimes generate invoices that need adjustment to meet full compliance standards.

Related Errors

Related Content

Last updated: 15 April 2026

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