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.
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.
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
<cac:TaxSubtotal> <cbc:TaxAmount><!-- invalid or missing value --></cbc:TaxAmount> </cac:TaxSubtotal>
<cac:TaxSubtotal> <cbc:TaxAmount>correct-value</cbc:TaxAmount> </cac:TaxSubtotal>
Technical Reference
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 Content
Last updated: 3 March 2026
Detect BR-CO-17 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.