KSeF and FA(3) checks
36 rules, version KSeF 2.0 invoice verification (9 April 2026), FA(3) information sheet (August 2026), published by xmlvalid, after the Ministry of Finance's KSeF 2.0 documentation and its information sheet on the FA(3) structure (MIT, source). Checked with KSeF FA(3)
- XV-PL-01 KSeF rejects an invoice with an XML processing instruction (…); leave out instructions such as xml-stylesheet (KSeF 2.0, weryfikacja faktury).
- XV-PL-02 KSeF rejects an invoice with a discouraged Unicode character: U+… in … (KSeF 2.0, weryfikacja faktury).
- XV-PL-03 The NIP … of … has no valid check digit; KSeF's production environment rejects the invoice (KSeF 2.0, weryfikacja faktury).
- 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).
- XV-PL-05 warning KSeF accepts an invoice with an attachment (Zalacznik) only from a seller who has registered the option in e-Urząd Skarbowy, and only in a batch session (KSeF 2.0, weryfikacja faktury).
- XV-PL-10 An invoice in PLN has no converted tax (…); those fields are for an invoice in a foreign currency (FA(3) information sheet, P_14_1W).
- XV-PL-11 An invoice in … must give its tax in PLN as well; missing: … (VAT Act, art. 106e ust. 11; FA(3) information sheet, P_14_1W).
- XV-PL-12 P_15 (…) must be the sum of the net amounts P_13_1 to P_13_11 and the tax P_14_1 to P_14_5 (…) (FA(3) information sheet, P_15).
- XV-PL-13 warning The tax is not the rate applied to its net amount: … (rates 23 or 22, 8 or 7, 5 %; per line rounding allowed) (FA(3) information sheet, P_14_1).
- XV-PL-14 The sums per rate do not match the lines: …. Each P_13 field is the sum of the net values (P_11) of the lines at its rate, or of their gross values (P_11A) less the tax (FA(3) information sheet, P_13_1, P_11).
- XV-PL-15 A corrective invoice (…) must name the invoice it corrects in DaneFaKorygowanej (VAT Act, art. 106j ust. 2; FA(3) information sheet, DaneFaKorygowanej).
- XV-PL-16 … belong to a corrective invoice (KOR, KOR_ZAL, KOR_ROZ), not to … (FA(3) information sheet, PrzyczynaKorekty).
- XV-PL-17 StanPrzed belongs to a correction of an invoice or a final invoice (KOR, KOR_ROZ), StanPrzedZ and KursWalutyZK to a correction of an advance invoice (KOR_ZAL), and P_15ZK to a correction of an advance or final invoice (KOR_ZAL, KOR_ROZ); this one is … (FA(3) information sheet, StanPrzed, P_15ZK).
- XV-PL-18 A final invoice (ROZ) must name the advance invoices it settles in FakturaZaliczkowa (VAT Act, art. 106f ust. 3; FA(3) information sheet, NrFaZaliczkowej).
- XV-PL-19 An advance invoice (ZAL) must describe the order or contract and its value in Zamowienie (VAT Act, art. 106f ust. 1 pkt 4; FA(3) information sheet, Zamowienie).
- XV-PL-20 Zamowienie is for an advance invoice (ZAL) and its correction (KOR_ZAL), not for … (FA(3) information sheet, Zamowienie).
- XV-PL-21 WartoscZamowienia (…) must be the sum of P_11NettoZ and P_11VatZ of the order lines (…) (FA(3) information sheet, WartoscZamowienia).
- XV-PL-22 A simplified invoice (UPR) may be issued up to PLN 450 or EUR 100 due; P_15 is … … (VAT Act, art. 106e ust. 5 pkt 3).
- XV-PL-23 An invoice other than a simplified one must give the buyer's name and address (Podmiot2: Nazwa and Adres); only a simplified invoice (UPR) up to PLN 450 may name the buyer by NIP alone (VAT Act, art. 106e ust. 1 pkt 3; FA(3) information sheet, Podmiot2).
- XV-PL-24 JST 1 (the invoice concerns a subordinate local government unit) needs that unit in Podmiot3 with Rola 8, so that it receives the invoice in KSeF (FA(3) information sheet, JST).
- XV-PL-25 GV 1 (the invoice concerns a member of a VAT group) needs that member in Podmiot3 with Rola 10, so that it receives the invoice in KSeF (FA(3) information sheet, GV).
- XV-PL-26 An invoice with sales under the margin scheme (P_13_11 …) must carry the margin scheme note: P_PMarzy 1 with its kind (VAT Act, art. 106e ust. 1 pkt 20 to 22; FA(3) information sheet, P_PMarzy).
- XV-PL-27 An invoice with exempt sales (P_13_7 or a line at rate zw) must give the legal basis of the exemption: P_19 1 with P_19A, P_19B or P_19C (VAT Act, art. 106e ust. 1 pkt 19; FA(3) information sheet, P_19).
- XV-PL-28 An invoice with domestic reverse charge sales (P_13_10 or a line at rate oo) must carry the reverse charge note: P_18 1 (VAT Act, art. 106e ust. 1 pkt 18; FA(3) information sheet, P_18).
- XV-PL-29 An invoice over PLN 15,000 due (P_15 …) to a taxpayer, with goods or services of Annex 15 (P_12_Zal_15), must carry the split payment note: P_18A 1 (VAT Act, art. 106e ust. 1 pkt 18a; FA(3) information sheet, P_18A).
- XV-PL-30 SumaObciazen and SumaOdliczen are the sums of the Kwota of the charges (…) and of the deductions (…) (FA(3) information sheet, SumaObciazen).
- XV-PL-31 … (…) must be P_15 plus the charges less the deductions (…), DoRozliczenia the overpayment when that is negative (FA(3) information sheet, DoZaplaty).
- XV-PL-32 The period of the invoice ends (P_6_Do …) before it starts (P_6_Od …) (FA(3) information sheet, OkresFa).
- XV-PL-33 A corrected invoice cannot be issued after its correction: DataWystFaKorygowanej … is later than P_1 … (FA(3) information sheet, DataWystFaKorygowanej).
- XV-PL-34 warning P_6 is for a date common to every line and P_6A for lines with different dates; this invoice has both (FA(3) information sheet, P_6).
- XV-PL-35 Line numbers repeat (NrWierszaFa or NrWierszaZam); each line has its own number, a line before a correction (StanPrzed) the number of the line it corrects (FA(3) information sheet, NrWierszaFa).
- XV-PL-36 warning Line …: … (…) is not the quantity times the unit price, less any discount (P_10), which is … (FA(3) information sheet, P_11).
- XV-PL-37 KursWaluty on an invoice line is the exchange rate of an invoice in a foreign currency; this invoice is in PLN (FA(3) information sheet, KursWaluty).
- XV-PL-38 warning In self-billing (P_17 1) the buyer issues the invoice as Podmiot2; it is not repeated in Podmiot3 with Rola 5 (FA(3) information sheet, P_17).
- XV-PL-39 An advance invoice documenting several payments has P_15 (…) equal to the sum of the payments P_15Z (…) (FA(3) information sheet, ZaliczkaCzesciowa).
- XV-PL-40 warning The payments received before the sale (P_15Z, …) exceed the amount due P_15 (…); P_15 less those payments is what remains to be paid (FA(3) information sheet, ZaliczkaCzesciowa).