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.Test This Error ↓

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

1.

Add TaxTotal

Required even if zero VAT

2.

Calculate amount

Sum of all TaxSubtotal TaxAmounts

3.

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 TaxAmount to TaxTotal element. You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.

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.

Many instances of BR-36 can be automatically corrected using Invoice Navigator's Fixer tool. Upload your invoice and the tool will identify and fix common issues, including tax total amount required.

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.

See Also

EN 16931 Validator

Check your invoice now

Related Errors

BR-CO-10

Sum of Invoice line net amount (BT-106) = Σ Invoice line net amount (BT-131).

BR-CO-13

Tax amount calculation error

Last updated: 27 February 2026

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