BR-AG-09:IPSI VAT breakdown tax amount must be calculated correctly
Fix: Invoice Navigator automatically fixes this issue by correcting the `cbc:TaxAmount` element in your Invoice. Upload your invoice to fix this automatically.
The tax amount for the IPSI VAT category in the VAT breakdown must be calculated based on the taxable amount and rate.
Engine Classification
Recalculate IPSI tax amount as taxableAmount times rate per EN16931 BR-AG-09
Confidence: 90% · Applied automatically in pipeline
What is BR-AG-09?
BR-AG-09 is a fatal validation rule defined in the EN 16931 specification. It validates the TaxAmount element under TaxSubtotal[cac:TaxCategory > ID='M'] in the UBL invoice XML.
When this rule fires, the invoice is rejected by Peppol access points and never reaches the buyer.
Target path: //cac:TaxTotal/cac:TaxSubtotal[cac:TaxCategory/cbc:ID='M']/cbc:TaxAmount
Why This Error Matters
Invoice will be rejected. IPSI (Ceuta/Melilla indirect tax) transactions must follow specific rules for Spanish territory tax compliance.
BR-AG-09 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.
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-AG-09
- ·Specification: EN 16931
How to Fix It
Locate IPSI VAT breakdown
Check tax amount calculation
Fix incorrect tax amount
Validate the result
Before / After
<cac:TaxSubtotal> <cbc:TaxAmount>999.99</cbc:TaxAmount> <!-- Does not match expected calculation --> </cac:TaxSubtotal>
<cac:TaxSubtotal> <cbc:TaxAmount>100.00</cbc:TaxAmount> <!-- Matches expected calculation --> </cac:TaxSubtotal>
Technical Reference
//cac:TaxTotal/cac:TaxSubtotal[cac:TaxCategory/cbc:ID='M']/cbc:TaxAmountCommon Causes
- ·IPSI tax amount calculation is incorrect
- ·Tax amount does not equal taxable × rate for IPSI
- ·Rounding error in IPSI tax calculation
- ·Manual tax override created mismatch
- ·Tax engine calculation differs from expected formula
Seeing this in production? The API handles BR-AG-09 automatically. See the fix response →
Frequently Asked Questions
The tax amount for the IPSI VAT category in the VAT breakdown must be calculated based on the taxable amount and rate.
Invoice Navigator automatically fixes this issue by correcting the `cbc:TaxAmount` element in your Invoice. You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.
Yes, BR-AG-09 is a critical error that will cause invoice rejection. It must be fixed before submission.
Many instances of BR-AG-09 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.
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Last updated: 27 February 2026
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