errorEN 16931

BR-45:Each VAT breakdown (BG-23) shall have a VAT category taxable amount (BT-116).

Each VAT breakdown (BG-23) shall have a VAT category taxable amount (BT-116).. Check the `cac:TaxSubtotal` element in your invoice XML.

Severity
Fatal
Rule set
EN 16931
Country
All EU
Fix type
BLOCKED

Engine Classification

Financial or legal field · Modification blocked by policy

Reason: Billing period for service lines affects revenue recognition and tax treatment. Must be set according to service delivery terms.

What is BR-45?

BR-45 is a fatal validation rule defined in the EN 16931 specification. It validates the InvoicePeriod element under Invoice > InvoiceLine 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: XPath: /Invoice/cac:InvoiceLine/cac:InvoicePeriod

This error requires manual correction — financial fields are protected by policy.Test This Error ↓

Why This Error Matters

Invoice rejected. Cannot verify VAT calculation without knowing the taxable base.

BR-45 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.

Validator Behavior

  • ·Causes invoice rejection
  • ·Error returned: BR-45
  • ·Specification: EN 16931

How to Fix It

1.

Add period

InvoicePeriod with StartDate and EndDate

2.

Format dates

YYYY-MM-DD format

3.

Optional on header

Or add to document-level InvoicePeriod

Before / After

Failing XML
<cac:TaxTotal>
  <!-- cac:TaxSubtotal is missing -->
</cac:TaxTotal>
Corrected XML
<cac:TaxTotal>
  <cac:TaxSubtotal>valid-value</cac:TaxSubtotal>
</cac:TaxTotal>

Technical Reference

XPathXPath: /Invoice/cac:InvoiceLine/cac:InvoicePeriod
SpecEN 16931
StrategyBLOCKED: This is a tax base amount. We cannot calculate taxable amounts - they must match the sum of line items in each VAT category. Source system must provide.

Code Example

<cac:InvoiceLine>
  <cbc:ID>1</cbc:ID>
  <cac:InvoicePeriod>
    <cbc:StartDate>2024-12-01</cbc:StartDate>
    <cbc:EndDate>2024-12-31</cbc:EndDate>
  </cac:InvoicePeriod>
  <!-- line content -->
</cac:InvoiceLine>

Common Causes

  • ·VAT breakdown missing taxable amount (TaxableAmount)
  • ·Tax subtotal created without tax base value
  • ·TaxSubtotal/TaxableAmount not mapped in export
  • ·VAT calculation skipped taxable amount field
  • ·Tax category present but base amount missing

Seeing this in production? The API handles BR-45 automatically. See the fix response →

Commonly Seen In

All invoicing software

Frequently Asked Questions

Service lines should specify the billing period.

Add InvoicePeriod to service lines. You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.

BR-45 is a warning that may not always cause rejection, but it indicates a potential compliance issue that should be addressed to ensure full compatibility.

Many instances of BR-45 can be automatically corrected using Invoice Navigator's Fixer tool. Upload your invoice and the tool will identify and fix common issues, including invoice line period for services.

BR-45 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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