Invoice Navigator automatically fixes this issue by correcting the `cac:CardAccount` element in your Invoice. You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.

Is BR-66 a critical error?

Yes, BR-66 is a critical error that will cause invoice rejection. It must be fixed before submission.

Can BR-66 be automatically fixed?

Many instances of BR-66 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.

errorEN 16931

`BR-66`:An Invoice shall contain maximum one Payment Card account (BG-18).

The invoice contains multiple Payment Card accounts (BG-18). Only one card payment method is allowed per invoice.

Severity

Fatal

Rule set

EN 16931

Country

All EU

Fix type

AUTO-FIX

Confidence

85%

Engine Classification

Recalculate line extension amount from quantity and price

Confidence: 85% · Applied automatically in pipeline

What is BR-66?

BR-66 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

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Why This Error Matters

Invoice rejected. Ambiguous payment instructions - which card should be used?

BR-66 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-66
·Specification: EN 16931

How to Fix It

Locate Payment Card sections

Count Payment Card accounts

Compare card details

Keep first or flag for review

Remove duplicate sections

Validate the result

Before / After

Failing XML

<cac:PaymentMeans>
  <cac:CardAccount><!-- invalid or missing value --></cac:CardAccount>
</cac:PaymentMeans>

Corrected XML

<cac:PaymentMeans>
  <cac:CardAccount>correct-value</cac:CardAccount>
</cac:PaymentMeans>

Technical Reference

XPath//cac:InvoiceLine/cbc:LineExtensionAmount

SpecEN 16931

Operationrecalculate

StrategyRecalculate line extension amount from quantity and price

Common Causes

·Multiple PaymentCard sections added to invoice
·ERP allows multiple card payment options but EN16931 only permits one
·Template duplicated payment card section
·Data migration merged multiple payment records
·Manual XML editing introduced duplicate card details

Seeing this in production? The API handles BR-66 automatically. See the fix response →

Related Errors

DE-R-024-1

Payment card details missing. When payment code 48, 54, or 55 (payment card)...

Last updated: 27 February 2026

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Handle BR-66 Automatically in Your Pipeline

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

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BR-66:An Invoice shall contain maximum one Payment Card account (BG-18).