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.Get API Access

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

Check category

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

Zero categories

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

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.

Update the `cbc:ID` element to use a value from the allowed code list. This error involves a protected field — Invoice Navigator flags it in your pipeline so your team can correct it at the source.

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

Detect IN-TAX-CATEGORY-CODES 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.

Get API Access View API Documentation

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