How do I fix BR-O-08?

Invoice Navigator automatically fixes this issue by correcting the `cac:TaxSubtotal` element in your Invoice (BR-O-08). You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.

Is BR-O-08 a critical error?

Yes, BR-O-08 is a critical error that will cause invoice rejection. It must be fixed before submission.

Can BR-O-08 be automatically fixed?

Many instances of BR-O-08 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.

errorEN 16931

`BR-O-08`:The taxable amount for this VAT category must equal the sum of line amounts...

The taxable amount for this VAT category must equal the sum of line amounts minus allowances plus charges for this category (applies to `cac:TaxSubtotal`, rule BR-O-08).

Severity

Fatal

Rule set

EN 16931

Country

All EU

Fix type

AUTO-FIX

Confidence

90%

Engine Classification

Recalculate taxable amount from sum of Not subject to VAT line amounts per EN16931 BR-O-08

Confidence: 90% · Applied automatically in pipeline

What is BR-O-08?

BR-O-08 is a fatal validation rule defined in the EN 16931 specification. It validates the TaxableAmount element under TaxSubtotal[cac:TaxCategory > ID='O'] 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: //cac:TaxTotal/cac:TaxSubtotal[cac:TaxCategory/cbc:ID='O']/cbc:TaxableAmount

Get API Access Test This Error ↓

Why This Error Matters

Invoice will be rejected. "Not subject to VAT" (category O) has strict rules: no VAT identifiers allowed, no other categories permitted, and exemption reason required. Non-compliance prevents validation.

BR-O-08 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.

Invoice Navigator can automatically correct this error in your pipeline. The fix is applied with full audit evidence, so your compliance trail remains intact.

Validator Behavior

·Causes invoice rejection
·Error returned: BR-O-08
·Specification: EN 16931

Before / After

Failing XML

<cac:TaxTotal>
  <cac:TaxSubtotal>999.99</cac:TaxSubtotal>
  <!-- Does not match expected calculation -->
</cac:TaxTotal>

Corrected XML

<cac:TaxTotal>
  <cac:TaxSubtotal>100.00</cac:TaxSubtotal>
  <!-- Matches expected calculation -->
</cac:TaxTotal>

Technical Reference

XPath//cac:TaxTotal/cac:TaxSubtotal[cac:TaxCategory/cbc:ID='O']/cbc:TaxableAmount

SpecEN 16931

Operationrecalculate

StrategyRecalculate taxable amount from sum of Not subject to VAT line amounts per EN16931 BR-O-08

Common Causes

·Category O taxable amount does not match line sum
·BT-116 in O breakdown incorrect calculation
·Sum of O category lines minus allowances plus charges wrong
·Taxable base calculation error for out-of-scope items
·O breakdown amount mismatch with categorized amounts

Seeing this in production? The API handles BR-O-08 automatically. See the fix response →

Related Errors

BR-24

Amount currency must match document currency

BR-32

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

BR-37

Each Document level charge (BG-21) shall have a Document level charge VAT...

Last updated: 27 February 2026

Share this guide:

Handle BR-O-08 Automatically in Your Pipeline

The compliance engine auto-remediates this error with controlled safety policies and evidence pack generation.

Get API Access View API Documentation

BR-O-08:The taxable amount for this VAT category must equal the sum of line amounts...