errorPOLubl-2.1

PL-R-003:KSeF submission required

Polish invoices must be submitted to KSeF (Krajowy System e-Faktur).

Severity
Fatal
Rule set
ubl-2.1
Country
POL
Fix type
BLOCKED

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 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: XPath: Extension for KSeF reference

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

Why This Error Matters

Polish B2B invoices must go through KSeF from 2026.

PL-R-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
  • ·Fails UBL schema validation
  • ·Error returned: PL-R-003
  • ·Specification: ubl-2.1

How to Fix It

1.

Submit to KSeF

Via KSeF API or portal

2.

Get reference

KSeF assigns unique number

3.

Include reference

Add to invoice for recipients

XML Example

Generic example based on the rule's target XPath. Your actual XML structure may differ.

Before
<!-- Triggers validation error -->
<XPath: Extension for KSeF reference></XPath: Extension for KSeF reference>
After
<!-- Corrected -->
<XPath: Extension for KSeF reference>VALID_VALUE</XPath: Extension for KSeF reference>

Technical Reference

XPathXPath: Extension for KSeF reference
Specubl-2.1

Common 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. You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.

Yes, PL-R-003 is a critical error that will cause invoice rejection. It must be fixed before submission.

Related Errors

Last updated: 27 February 2026

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Handle PL-R-003 Automatically in Your Pipeline

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