FORMAT-003:Incorrect XML attachment filename
Factur-X XML must be named correctly.
Engine Classification
Financial or legal field · Modification blocked by policy
Reason: Factur-X requires the embedded XML to be named "factur-x.xml" (or "zugferd-invoice.xml" for ZUGFeRD). The PDF must be regenerated with the correctly named XML attachment. This cannot be fixed by editing the XML alone.
What is FORMAT-003?
FORMAT-003 is a fatal validation rule defined in the factur-x specification. It validates the PDF attachment filename check 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: PDF attachment filename check
Why This Error Matters
Filename identifies the XML type.
FORMAT-003 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.
Validator Behavior
- ·Causes invoice rejection
- ·Error returned: FORMAT-003
- ·Specification: factur-x
How to Fix It
Check filename
factur-x.xml for Factur-X
Rename if needed
Exact filename required
XML Example
Generic example based on the rule's target XPath. Your actual XML structure may differ.
<!-- Triggers validation error --> <PDF attachment filename check></PDF attachment filename check>
<!-- Corrected --> <PDF attachment filename check>VALID_VALUE</PDF attachment filename check>
Technical Reference
PDF attachment filename checkCommon Causes
- ·Wrong filename
- ·Missing attachment
Seeing this in production? The API handles FORMAT-003 automatically. See the fix response →
Frequently Asked Questions
Factur-X XML must be named correctly.
Name XML attachment according to profile. This error involves a protected field — Invoice Navigator flags it in your pipeline so your team can correct it at the source.
Yes, FORMAT-003 is a critical error that must be fixed.
Related Content
Last updated: 3 March 2026
Detect FORMAT-003 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.