BR-AG-01:IPSI VAT breakdown required when IPSI used on lines
Fix: Recalculate the value in `cac:InvoiceLine` to match the expected formula. Verify all contributing amounts are correct (BR-AG-01).
When using the IPSI VAT category (M) on invoice lines, allowances, or charges, you must have exactly one matching VAT breakdown section for IPSI.
Engine Classification
Financial or legal field · Modification blocked by policy
What is BR-AG-01?
BR-AG-01 is a fatal validation rule defined in the EN 16931 specification. It validates the ID="M"]. IPSI (category M) is the Ceuta and Melilla indirect tax. When lines or document-level items use this category, the VAT breakdown must include a corresponding TaxSubtotal. element under TaxTotal > TaxSubtotal[cac:TaxCategory in the UBL invoice XML.
When this rule fires, the invoice is rejected by Peppol access points and never reaches the buyer.
Target path: XPath: /Invoice/cac:TaxTotal/cac:TaxSubtotal[cac:TaxCategory/cbc:ID="M"]. IPSI (category M) is the Ceuta and Melilla indirect tax. When lines or document-level items use this category, the VAT breakdown must include a corresponding TaxSubtotal.
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-01 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.
Validator Behavior
- ·Causes invoice rejection
- ·Error returned: BR-AG-01
- ·Specification: EN 16931
How to Fix It
Find IPSI lines/allowances/charges
Check for IPSI VAT breakdown
Create IPSI breakdown if missing
Ensure only one IPSI breakdown
Validate the result
Before / After
<Invoice> <cac:InvoiceLine>999.99</cac:InvoiceLine> <!-- Does not match expected calculation --> </Invoice>
<Invoice> <cac:InvoiceLine>100.00</cac:InvoiceLine> <!-- Matches expected calculation --> </Invoice>
Technical Reference
XPath: /Invoice/cac:TaxTotal/cac:TaxSubtotal[cac:TaxCategory/cbc:ID="M"]. IPSI (category M) is the Ceuta and Melilla indirect tax. When lines or document-level items use this category, the VAT breakdown must include a corresponding TaxSubtotal.Common Causes
- ·IPSI tax category used on lines but missing from VAT breakdown
- ·Tax breakdown not generated for Ceuta/Melilla IPSI transactions
- ·VAT summary calculation skipped IPSI category
- ·Export template missing IPSI breakdown section
- ·Tax engine not configured for IPSI category code L
Seeing this in production? The API handles BR-AG-01 automatically. See the fix response →
Frequently Asked Questions
When using the IPSI VAT category (M) on invoice lines, allowances, or charges, you must have exactly one matching VAT breakdown section for IPSI.
Recalculate the value in `cac:InvoiceLine` to match the expected formula. Verify all contributing amounts are correct (BR-AG-01). You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.
Yes, BR-AG-01 is a critical error that will cause invoice rejection. It must be fixed before submission.
Many instances of BR-AG-01 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: 3 March 2026
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