errorEN 16931

UBL-DT-06:Binary object elements shall contain the mime code attribute

Your invoice contains an embedded attachment (EmbeddedDocumentBinaryObject) but the mimeCode attribute is missing. The MIME type (e.g., application/pdf, image/png) must be specified.

Severity
Fatal
Rule set
EN 16931
Country
All EU
Fix type
AUTO-FIX
Confidence
80%
Category
structural

Engine Classification

Add default mimeCode attribute (application/pdf) to embedded binary objects

Confidence: 80% · Applied automatically in pipeline

What is UBL-DT-06?

UBL-DT-06 is a fatal validation rule defined in the EN 16931 specification. It validates the @mimeCode element in the UBL invoice XML.

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.

Target path: //cbc:EmbeddedDocumentBinaryObject/@mimeCode

Why This Error Matters

Invoice will be rejected. Receiving systems need the MIME type to properly display or process the attachment.

UBL-DT-06 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.

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: UBL-DT-06
  • ·Specification: EN 16931

Before / After

Failing XML
<Invoice>
  <!-- Issue: Binary object elements shall contain the mime code attribute -->
</Invoice>
Corrected XML
<Invoice>
  <!-- Issue resolved per EN 16931 -->
</Invoice>

Technical Reference

XPath//cbc:EmbeddedDocumentBinaryObject/@mimeCode
SpecEN 16931
Operationset_default
StrategyAdd default mimeCode attribute (application/pdf) to embedded binary objects

Common Causes

  • ·Attachment added without specifying the file type
  • ·ERP export omitted the MIME type attribute
  • ·Binary content copied without metadata
  • ·Template missing mimeCode attribute on attachment element
  • ·File uploaded without extension or type detection

Seeing this in production? The API handles UBL-DT-06 automatically. See the fix response →

See Also

Last updated: 27 February 2026

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Handle UBL-DT-06 Automatically in Your Pipeline

The compliance engine auto-remediates this error with controlled safety policies and evidence pack generation.