BR-CO-10: Sum of line net amounts (BT-106) does not match the lines

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

BT-106 Sum of Invoice line net amount
BT-131 Invoice line net amount

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

Why this error occurs

The header total BT-106 must equal the sum of all invoice line net amounts (BT-131), rounded to two decimals. The rule compares cac:LegalMonetaryTotal/cbc:LineExtensionAmount with the sum of cac:InvoiceLine/cbc:LineExtensionAmount (UBL), or ram:SpecifiedTradeSettlementHeaderMonetarySummation/ram:LineTotalAmount with the sum of the line ram:LineTotalAmount values (CII). Mismatches come from software summing unrounded internal values while writing rounded values per line, or from lines being dropped or filtered in the export.

How to fix it

Formula: BT-106 = Σ BT-131 over all lines, rounded to 2 decimals. Compute the header value from the exact amounts written into the XML lines, not from internal full-precision values. In UBL set cbc:LineExtensionAmount in cac:LegalMonetaryTotal; in CII set ram:LineTotalAmount in the header monetary summation. Negative lines (credits) are included with their sign; document-level allowances and charges are not part of this sum.

Example (valid)

<cac:LegalMonetaryTotal>
  <cbc:LineExtensionAmount currencyID="EUR">250.00</cbc:LineExtensionAmount>
  <cbc:TaxExclusiveAmount currencyID="EUR">250.00</cbc:TaxExclusiveAmount>
  <cbc:TaxInclusiveAmount currencyID="EUR">297.50</cbc:TaxInclusiveAmount>
  <cbc:PayableAmount currencyID="EUR">297.50</cbc:PayableAmount>
</cac:LegalMonetaryTotal>

What the validator checks

Checked element (context):

UBL

cac:LegalMonetaryTotal

Test (XPath):

(xs:decimal(cbc:LineExtensionAmount) = xs:decimal(round(sum(//(cac:InvoiceLine|cac:CreditNoteLine)/xs:decimal(cbc:LineExtensionAmount)) * 10 * 10) div 100))

CII

//ram:SpecifiedTradeSettlementHeaderMonetarySummation

Test (XPath):

xs:decimal(ram:LineTotalAmount) = round(xs:decimal(sum(../../ram:IncludedSupplyChainTradeLineItem/ram:SpecifiedLineTradeSettlement/ram:SpecifiedTradeSettlementLineMonetarySummation/ram:LineTotalAmount)) * xs:decimal(100)) div xs:decimal(100)

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Same check via API:

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Related rules

BR-CO-13 Total without VAT (BT-109) does not add up
BR-12 An Invoice shall have the Sum of Invoice line net amount
BR-24 Each Invoice line shall have an Invoice line net amount
BR-AE-08 In a VAT breakdown where the VAT category code is "Reverse charge" the VAT category…
BR-AF-08 For each different value of VAT category rate where the VAT category code is "IGIC",…
BR-AG-08 For each different value of VAT category rate where the VAT category code is "IPSI",…
BR-DEC-09 The allowed maximum number of decimals for the Sum of Invoice line net amount is 2
BR-DEC-23 Invoice line net amount (BT-131) has more than 2 decimals

Frequently asked questions

What does BR-CO-10 mean?

BR-CO-10 is a en 16931 core rule: Sum of Invoice line net amount (BT-106) = Σ Invoice line net amount (BT-131).

Will my invoice be rejected because of BR-CO-10?

Yes. BR-CO-10 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-CO-10 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.