errorEN 16931

`BR-36`:Tax total amount required

Each Document level charge (BG-21) shall have a Document level charge amount (BT-99).. 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: Invoice totals require manual verification. Automatic changes could cause calculation cascades affecting tax amounts, line totals, and compliance. Please verify all amounts in your source system.

What is BR-36?

BR-36 is a fatal validation rule defined in the EN 16931 specification. It validates the TaxAmount element under Invoice > TaxTotal 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:TaxTotal/cbc:TaxAmount

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

Why This Error Matters

Invoice rejected. Cannot calculate invoice totals without charge amounts.

BR-36 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-36
·Specification: EN 16931

How to Fix It

Add TaxTotal

Required even if zero VAT

Calculate amount

Sum of all TaxSubtotal TaxAmounts

Include currency

currencyID must match DocumentCurrencyCode

Before / After

Failing XML

<Invoice>
  <!-- cac:AllowanceCharge is missing -->
</Invoice>

Corrected XML

<Invoice>
  <cac:AllowanceCharge>valid-value</cac:AllowanceCharge>
</Invoice>

Technical Reference

XPathXPath: /Invoice/cac:TaxTotal/cbc:TaxAmount

SpecEN 16931

StrategyBLOCKED: This is a monetary amount. We cannot determine what the charge should be - it could be shipping, handling, or other fees. Source system must provide.

Code Example

<cac:TaxTotal>
  <cbc:TaxAmount currencyID="EUR">210.00</cbc:TaxAmount>
  <!-- TaxSubtotals -->
</cac:TaxTotal>

Common Causes

·Document charge added without amount value
·AllowanceCharge/Amount field not mapped for charges
·Percentage surcharge without base amount
·Charge template missing amount field mapping
·Zero-value charge exported with null instead of 0

Seeing this in production? The API handles BR-36 automatically. See the fix response →

Commonly Seen In

All invoicing software

Frequently Asked Questions

The invoice must have a TaxTotal with TaxAmount.

Add the required `cac:AllowanceCharge` element to your Invoice. Ensure it contains a valid value per EN 16931 (BR-36). This error involves a protected field — Invoice Navigator flags it in your pipeline so your team can correct it at the source.

Yes, BR-36 is a critical error that will cause invoice rejection. It must be fixed before submission to ensure your invoice is accepted by the recipient's system.

BR-36 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-36 is commonly seen in exports from All invoicing software. These software packages sometimes generate invoices that need adjustment to meet full compliance standards.

Detect BR-36 Before Submission

This error involves a financial or legal field that cannot be auto-modified. The compliance engine flags it immediately with a clear diagnosis so your team can fix it at the source.

Get API Access View API Documentation

BR-36:Tax total amount required