BR-55:Prepayment should reference prepayment invoice
Fix: This requires user input to resolve. Provide the correct reference in `cac:BillingReference` for the PrepaidAmount Invoice. Provide the required value in the free validator.
When PrepaidAmount is used, reference the prepayment invoice.
Engine Classification
Business data required · Explicit input workflow · No assumptions made
Required input: Prepayment Invoice Number
What is BR-55?
BR-55 is a warning validation rule defined in the EN 16931 specification. It validates the PrepaidPayment element under Invoice in the UBL invoice XML.
The invoice may pass transmission, but this non-compliance can cause problems during tax audits or buyer-side processing.
Target path: XPath: /Invoice/cac:PrepaidPayment
Why This Error Matters
Invoice rejected. Credit notes and corrections must reference the original invoice for reconciliation.
BR-55 is a soft failure that can cause issues at the receiving end — tax audits, ERP processing, or VAT reconciliation mismatches.
Validator Behavior
- ·Generates validation warning
- ·Error returned: BR-55
- ·Specification: EN 16931
How to Fix It
Add PrepaidPayment
If PrepaidAmount in totals
Reference invoice
ID of prepayment/advance invoice
Include amount
PaidAmount matches PrepaidAmount
Before / After
<Invoice> <!-- Issue: When PrepaidAmount is used, reference the prepayment invoice --> </Invoice>
<Invoice> <!-- Issue resolved per EN 16931 --> </Invoice>
Technical Reference
XPath: /Invoice/cac:PrepaidPaymentCode Example
<cac:PrepaidPayment>
<cbc:ID>ADV-2024-00123</cbc:ID>
<cbc:PaidAmount currencyID="EUR">200.00</cbc:PaidAmount>
<cbc:ReceivedDate>2024-11-01</cbc:ReceivedDate>
</cac:PrepaidPayment>
<cac:LegalMonetaryTotal>
<cbc:PrepaidAmount currencyID="EUR">200.00</cbc:PrepaidAmount>
</cac:LegalMonetaryTotal>Common Causes
- ·Preceding invoice reference section without invoice number
- ·BillingReference/InvoiceDocumentReference/ID empty
- ·Credit note referencing invoice but number not filled
- ·Template has reference structure but ID not mapped
- ·Related invoice number stored in wrong field
Seeing this in production? The API handles BR-55 automatically. See the fix response →
Commonly Seen In
Frequently Asked Questions
When PrepaidAmount is used, reference the prepayment invoice.
This requires user input to resolve. Provide the correct reference in `cac:BillingReference` for the PrepaidAmount Invoice. Invoice Navigator detects this error and prompts for the required business data before applying a safe fix.
BR-55 is a warning that may not always cause rejection, but it indicates a potential compliance issue that should be addressed to ensure full compatibility.
BR-55 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-55 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: 3 March 2026
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