How do I fix BR-CO-17?

A VAT Category Tax Amount (BT-117) doesn't equal the Taxable Amount (BT-116) multiplied by the Rate (BT-119). The tax calculation is mathematically wrong. You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.

Is BR-CO-17 a critical error?

Yes, BR-CO-17 is a critical error that will cause invoice rejection. It must be fixed before submission.

Can BR-CO-17 be automatically fixed?

Many instances of BR-CO-17 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.

errorEN 16931

`BR-CO-17`:A VAT Category Tax Amount (BT-117) doesn't equal the Taxable Amount (BT-116)...

A VAT Category Tax Amount (BT-117) doesn't equal the Taxable Amount (BT-116) multiplied by the Rate (BT-119). The tax calculation is mathematically wrong.

Severity

Fatal

Rule set

EN 16931

Country

All EU

Fix type

BLOCKED

Engine Classification

Financial or legal field · Modification blocked by policy

Reason: Tax amount calculations have legal compliance implications. The calculated tax must match your tax determination rules and rates.

What is BR-CO-17?

BR-CO-17 is a fatal validation rule defined in the EN 16931 specification. It checks whether a vat category tax amount (bt-117) doesn't equal the taxable amount (bt-116)....

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.

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

Why This Error Matters

Invoice rejected. Incorrect tax calculation causes VAT reporting errors and potential penalties.

BR-CO-17 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-CO-17
·Specification: EN 16931

Before / After

Failing XML

<cac:TaxSubtotal>
  <cbc:TaxAmount><!-- invalid or missing value --></cbc:TaxAmount>
</cac:TaxSubtotal>

Corrected XML

<cac:TaxSubtotal>
  <cbc:TaxAmount>correct-value</cbc:TaxAmount>
</cac:TaxSubtotal>

Technical Reference

SpecEN 16931

StrategyBLOCKED: This is a tax calculation error. We cannot recalculate because country-specific rounding rules apply, and we don't know which value is wrong. Source system must recalculate using proper tax rules.

Common Causes

·VAT category tax amount calculation incorrect
·BT-117 does not equal BT-116 × rate / 100
·Rounding error in tax calculation
·Tax amount manually overridden incorrectly
·Tax engine uses different rounding than expected

Seeing this in production? The API handles BR-CO-17 automatically. See the fix response →

Related Errors

BR-45

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

BR-48

Document allowance tax category required

BR-AE-09

Reverse charge VAT breakdown tax amount must be zero

Last updated: 27 February 2026

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Handle BR-CO-17 Automatically in Your Pipeline

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

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BR-CO-17:A VAT Category Tax Amount (BT-117) doesn't equal the Taxable Amount (BT-116)...