Engine Classification
Financial or legal field · Modification blocked by policy
Reason: Polish invoices must be submitted to KSeF (Krajowy System e-Faktur). This requires API integration with the Polish tax authority system and cannot be accomplished by modifying the invoice XML. Use invoicing software with KSeF integration, or submit manually through the KSeF portal.
What is PL-R-003?
PL-R-003 is a fatal validation rule defined in the ubl-2.1 specification (POL national rules). It validates the XPath: Extension for KSeF reference element 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: Extension for KSeF reference
Why This Error Matters
Polish B2B invoices must go through KSeF from 2026.
PL-R-003 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.
Validator Behavior
- ·Causes invoice rejection
- ·Fails UBL schema validation
- ·Error returned: PL-R-003
- ·Specification: ubl-2.1
How to Fix It
Submit to KSeF
Via KSeF API or portal
Get reference
KSeF assigns unique number
Include reference
Add to invoice for recipients
XML Example
Generic example based on the rule's target XPath. Your actual XML structure may differ.
<!-- Triggers validation error --> <XPath: Extension for KSeF reference></XPath: Extension for KSeF reference>
<!-- Corrected --> <XPath: Extension for KSeF reference>VALID_VALUE</XPath: Extension for KSeF reference>
Technical Reference
XPath: Extension for KSeF referenceCommon Causes
- ·Not submitted to KSeF
- ·Missing KSeF reference
Seeing this in production? The API handles PL-R-003 automatically. See the fix response →
Frequently Asked Questions
Polish invoices must be submitted to KSeF (Krajowy System e-Faktur).
Submit invoice to KSeF and include reference number. This error involves a protected field — Invoice Navigator flags it in your pipeline so your team can correct it at the source.
Yes, PL-R-003 is a critical error that will cause invoice rejection. It must be fixed before submission.
Related Errors
Related Content
Last updated: 3 March 2026
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