errorbusinessEN 16931

BR-31:Each Document level allowance (BG-20) shall have a Document level allowance...

Fix: Add the required `cac:AllowanceCharge` element to your Invoice. Ensure it contains a valid value per EN 16931.

Each Document level allowance (BG-20) shall have a Document level allowance amount (BT-92).. Check the `cac:AllowanceCharge` 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: Payment terms affect cash flow and contractual obligations. Due dates must be set according to your business agreements.

What is BR-31?

BR-31 is a fatal validation rule defined in the EN 16931 specification. It validates the Note element under Invoice > PaymentTerms in the UBL invoice XML.

When this rule fires, the invoice is rejected by Peppol access points and never reaches the buyer.

Target path: XPath: /Invoice/cbc:DueDate or /Invoice/cac:PaymentTerms/cbc:Note

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

Why This Error Matters

Invoice rejected. Cannot calculate invoice totals without allowance amounts.

BR-31 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.

Validator Behavior

  • ·Causes invoice rejection
  • ·Error returned: BR-31
  • ·Specification: EN 16931

How to Fix It

1.

Add DueDate

Specific date in YYYY-MM-DD format

2.

Or PaymentTerms

Describe terms like Net 30

3.

Calculate from issue

DueDate = IssueDate + payment terms

Before / After

Failing XML
<Invoice>
  <!-- cac:AllowanceCharge is missing -->
</Invoice>
Corrected XML
<Invoice>
  <cac:AllowanceCharge>valid-value</cac:AllowanceCharge>
</Invoice>

Technical Reference

XPathXPath: /Invoice/cbc:DueDate or /Invoice/cac:PaymentTerms/cbc:Note
SpecEN 16931
StrategyBLOCKED: This is a monetary amount. We cannot guess what the allowance should be - it could be a fixed amount, percentage, or negotiated discount. Source system must provide.

Code Example

<cbc:DueDate>2025-01-18</cbc:DueDate>
<cac:PaymentTerms>
  <cbc:Note>Payment due within 30 days</cbc:Note>
</cac:PaymentTerms>

Common Causes

  • ·Document allowance added without amount value
  • ·AllowanceCharge/Amount field not mapped in export
  • ·Percentage discount without base amount to calculate
  • ·Allowance template missing amount field
  • ·Zero-value allowance exported with null instead of 0

Seeing this in production? The API handles BR-31 automatically. See the fix response →

Commonly Seen In

All invoicing software

Frequently Asked Questions

The invoice should specify when payment is due.

Add the required `cac:AllowanceCharge` element to your Invoice. Ensure it contains a valid value per EN 16931. This error involves a protected field — Invoice Navigator flags it in your pipeline so your team can correct it at the source.

BR-31 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-31 involves a financial or legal field that cannot be auto-modified by policy. Invoice Navigator detects and flags this error immediately, but the correction must be made manually in your ERP or invoicing software.

BR-31 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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