# XV-PL-04

Source: https://xmlvalid.com/rules/XV-PL-04

> The internal identifier … of Podmiot3 starts with a NIP that has no valid check digit; KSeF's production environment rejects the invoice (KSeF 2.0, weryfikacja faktury).

- Level: error
- Rule sets: KSeF and FA(3) checks KSeF 2.0 invoice verification (9 April 2026), FA(3) information sheet (August 2026)
- Context: `fa:Podmiot3/fa:DaneIdentyfikacyjne/fa:IDWew`
- Test: `pl:nip(substring(normalize-space(.), 1, 10))`

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