errorEN 16931

BR-CO-10:Sum of Invoice line net amount (BT-106) = Σ Invoice line net amount (BT-131).

Each VAT category taxable amount must be correctly calculated from line amounts.

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

Engine Classification

Recalculate LineExtensionAmount as InvoicedQuantity x PriceAmount

Confidence: 90% · Applied automatically in pipeline

What is BR-CO-10?

BR-CO-10 is a fatal validation rule defined in the EN 16931 specification. It validates the LineExtensionAmount element in the UBL invoice XML.

When this rule fires, the invoice is non-compliant and will be rejected by Peppol access points and national validation services. The sending system receives a rejection response and the invoice does not reach the buyer.

Target path: //cac:InvoiceLine/cbc:LineExtensionAmount

Why This Error Matters

Invoice rejected. The receiver's system will detect the calculation mismatch during validation.

BR-CO-10 is a hard failure. Invoices that trigger this rule are rejected at the access point and never reach the recipient. In Peppol networks, this means your sending system receives an MLR (Message Level Response) with a rejection status. The invoice must be corrected and re-sent, adding delay to your payment cycle.

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-CO-10
  • ·Specification: EN 16931

How to Fix It

1.

Group lines

By TaxCategory ID and Percent

2.

Sum line amounts

Add all LineExtensionAmount for group

3.

Add doc charges

Include document-level charges/allowances for that category

Before / After

Failing XML
<cac:LegalMonetaryTotal>
  <cbc:LineExtensionAmount>999.99</cbc:LineExtensionAmount>
  <!-- Does not match expected calculation -->
</cac:LegalMonetaryTotal>
Corrected XML
<cac:LegalMonetaryTotal>
  <cbc:LineExtensionAmount>100.00</cbc:LineExtensionAmount>
  <!-- Matches expected calculation -->
</cac:LegalMonetaryTotal>

Technical Reference

XPath//cac:InvoiceLine/cbc:LineExtensionAmount
SpecEN 16931
Operationrecalculate
StrategyRecalculate LineExtensionAmount as InvoicedQuantity x PriceAmount

Code Example

<cac:TaxSubtotal>
  <cbc:TaxableAmount currencyID="EUR">850.00</cbc:TaxableAmount>
  <cbc:TaxAmount currencyID="EUR">178.50</cbc:TaxAmount>
  <cac:TaxCategory>
    <cbc:ID>S</cbc:ID>
    <cbc:Percent>21</cbc:Percent>
  </cac:TaxCategory>
</cac:TaxSubtotal>

Common Causes

  • ·Sum of line net amounts does not match BT-106
  • ·LineExtensionAmount total calculation mismatch
  • ·Rounding errors accumulated across invoice lines
  • ·Manual adjustment to total without updating lines
  • ·Some lines excluded from sum calculation

Seeing this in production? The API handles BR-CO-10 automatically. See the fix response →

ERP-Specific Causes

Commonly Seen In

All invoicing software

Frequently Asked Questions

Each VAT category taxable amount must be correctly calculated from line amounts.

Recalculate TaxableAmount for each tax category. You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.

Yes, BR-CO-10 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.

Many instances of BR-CO-10 can be automatically corrected using Invoice Navigator's Fixer tool. Upload your invoice and the tool will identify and fix common issues, including sum of vat category amounts incorrect.

BR-CO-10 is commonly seen in exports from All invoicing software. These software packages sometimes generate invoices that need adjustment to meet full compliance standards.

See Also

Related Errors

Last updated: 27 February 2026

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Handle BR-CO-10 Automatically in Your Pipeline

The compliance engine auto-remediates this error with controlled safety policies and evidence pack generation.