warningPeppol BIS 3.0

IN-TAX-CATEGORY-CODES:Tax category codes validation

Tax category codes should be from UNCL5305 Peppol subset (AE, E, G, K, L, M, O, S, Z)

Severity
Warning
Rule set
Peppol BIS 3.0
Country
All EU
Fix type
BLOCKED

Engine Classification

Financial or legal field · Modification blocked by policy

Reason: Tax category codes affect tax calculation and reporting. The correct code must be determined based on the transaction type and applicable tax rules.

What is IN-TAX-CATEGORY-CODES?

IN-TAX-CATEGORY-CODES is a warning validation rule defined in the Peppol BIS 3.0 specification. It validates the Percent element under TaxCategory in the UBL invoice XML.

This is a soft validation failure. The invoice may pass initial transmission, but non-compliant values in this field can cause problems during tax audits, buyer-side processing, or downstream VAT reconciliation.

Target path: XPath: //cac:TaxCategory/cbc:Percent

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

Why This Error Matters

VAT rate must be correct for proper tax calculation and reporting.

IN-TAX-CATEGORY-CODES is a soft failure. The invoice may pass initial validation, but the non-compliant field can cause issues at the receiving end — tax authorities may flag it during audits, buyer ERP systems may fail to process it, or VAT reconciliation may produce mismatches. Fixing warnings before they accumulate prevents larger compliance gaps.

Validator Behavior

  • ·Generates validation warning
  • ·Rejected by PEPPOL Access Points
  • ·Error returned: IN-TAX-CATEGORY-CODES
  • ·Specification: Peppol BIS 3.0

How to Fix It

1.

Check category

S requires standard rate (19-27% in EU)

2.

Zero categories

Z, E, AE, K, G should have 0 or no percent

3.

Reduced rates

AA for reduced rate with applicable percentage

Before / After

Failing XML
<cac:TaxCategory>
  <cbc:ID>INVALID_CODE</cbc:ID>
</cac:TaxCategory>
Corrected XML
<cac:TaxCategory>
  <cbc:ID>VALID_CODE</cbc:ID>
</cac:TaxCategory>

Technical Reference

XPathXPath: //cac:TaxCategory/cbc:Percent
SpecPeppol BIS 3.0

Code Example

<cac:TaxCategory>
  <cbc:ID>S</cbc:ID>
  <cbc:Percent>21</cbc:Percent>
</cac:TaxCategory>

Common Causes

  • ·Wrong rate for country
  • ·Using 0% with S category
  • ·Invalid percentage value

Seeing this in production? The API handles IN-TAX-CATEGORY-CODES automatically. See the fix response →

Commonly Seen In

All invoicing software

Frequently Asked Questions

The VAT percentage must be a valid rate for the tax category.

Use valid VAT rate for the tax category. Invoice Navigator can help identify and fix this issue.

Yes, PEPPOL-EN16931-R007 is a critical error that must be fixed.

See Also

Peppol Validator

Check your invoice now

Related Errors

BR-21

Missing invoice line identifier

BR-S-08

Standard rated VAT amount doesn't add up

Last updated: 27 February 2026

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