errorPOLubl-2.1

PL-R-005:Invalid Polish NIP format

Polish NIP must be 10 digits with valid checksum.

Severity
Fatal
Rule set
ubl-2.1
Country
POL
Fix type
INPUT REQUIRED

Engine Classification

Business data required · Explicit input workflow · No assumptions made

Required input: Polish NIP Number

What is PL-R-005?

PL-R-005 is a fatal validation rule defined in the ubl-2.1 specification (POL national rules). It validates the CompanyID element under PartyTaxScheme 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: //cac:PartyTaxScheme/cbc:CompanyID

Why This Error Matters

Invalid NIP prevents KSeF submission and VAT verification.

PL-R-005 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-005
  • ·Specification: ubl-2.1

How to Fix It

1.

Check length

Must be exactly 10 digits

2.

Verify checksum

MOD 11 validation

XML Example

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

Before
<!-- Missing or empty element triggers cbc:CompanyID error -->
<cbc:CompanyID></cbc:CompanyID>
After
<!-- Provide the required value -->
<cbc:CompanyID>VALID_VALUE</cbc:CompanyID>

Technical Reference

XPathXPath: //cac:PartyTaxScheme/cbc:CompanyID
Specubl-2.1

Common Causes

  • ·Wrong length
  • ·Invalid checksum
  • ·Using old format

Seeing this in production? The API handles PL-R-005 automatically. See the fix response →

Frequently Asked Questions

Polish NIP must be 10 digits with valid checksum.

Use valid 10-digit NIP number. You can also use Invoice Navigator's automatic Fixer tool to correct this instantly.

Yes, PL-R-005 is a critical error that will cause invoice rejection. It must be fixed before submission.

Last updated: 27 February 2026

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