# Poland KSeF QR

> Source: https://docs.barcoder.ai/docs/standards/poland-ksef-qr
> research date 2026-10-30 · extracted at 2026-10-30
> Publisher: Barcoder — encyclopedia of QR, barcode and payment-code standards

Specifications:
- [Kody weryfikujące QR — KSeF 2.0 API documentation (Ministry of Finance)](https://raw.githubusercontent.com/CIRFMF/ksef-api/main/kody-qr.md)
- [Regulation of the Minister of Finance and Economy of 12 December 2025 on the use of KSeF (Dz. U. 2025 poz. 1815)](https://eli.gov.pl/eli/DU/2025/1815/ogl/pol/pdf)
- [Kody weryfikujące QR — Ministry of Finance KSeF portal](https://ksef.podatki.gov.pl/informacje-ogolne-ksef-20/kody-weryfikujace-qr/)

## Overview

The **KSeF verification QR codes** are the [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) symbols printed on visualisations of invoices from Poland's National e-Invoicing System (Krajowy System e-Faktur, KSeF), run by the Ministry of Finance. Polish law calls them the "kod weryfikujący" and the code proving "authenticity of origin and integrity of content"; the ministry's documentation calls them **KOD I** and **KOD II** <sup>[1][1]</sup> <sup>[5][5]</sup>.

Each is a [URL QR](https://docs.barcoder.ai/docs/standards/url-qr): an `https://` link built locally by the invoicing software, not issued by the tax authority <sup>[5][5]</sup>. KOD I links a printed or PDF invoice to the XML copy in KSeF through its SHA-256 hash. KOD II, used only on offline invoices not yet sent to KSeF, adds a signature that identifies the issuer <sup>[4][4]</sup> <sup>[5][5]</sup>. Neither is a payment code <sup>[22][22]</sup>.

## History

- **16 June 2023.** The Act of this date (Dz. U. 2023 poz. 1598) set 1 July 2024 as its main commencement date. It already required a code giving access to the invoice in KSeF and allowing its data to be checked, when a structured invoice is handed over or used outside KSeF (art. 106gb(5) of the VAT Act) <sup>[3][3]</sup>.
- **October 2023.** The training firm Akademia LTCA relayed a reply from KSeF support on an open design problem: an invoice issued offline has no KSeF number yet to link to. Support said detail would follow the implementing regulation <sup>[19][19]</sup>. The published design links through the invoice hash, seller NIP and date instead <sup>[5][5]</sup>.
- **December 2023.** Per the tax-compliance vendor Sovos, specification 1.5 for the KSeF test environment described the QR codes and verification links and required ISO/IEC 18004:2015 <sup>[18][18]</sup>. The current regulation requires the 2024 edition <sup>[1][1]</sup>.
- **9 May 2024.** An amending act (Dz. U. 2024 poz. 852) moved the mandatory start to 1 February 2026 <sup>[15][15]</sup>.
- **5 August 2025.** A second amending act (Dz. U. 2025 poz. 1203, published 1 September 2025) created the voluntary offline mode, art. 106nda, and the second code. It also extended the code duty to entities other than the taxpayer <sup>[2][2]</sup>.
- **21 August 2025.** Date on the KSeF 2.0 QR guide <sup>[5][5]</sup>.
- **12 December 2025.** The implementing regulation (Dz. U. 2025 poz. 1815, published 18 December 2025) fixed the contents and labels, effective 1 February 2026 <sup>[1][1]</sup>.
- **1 February 2026.** QR codes began to apply in production. Invoices from the earlier voluntary period need not carry them <sup>[9][9]</sup>.

## Technical specification

| Property | Value |
|---|---|
| Symbology | QR Code, ISO/IEC 18004:2024 <sup>[1][1]</sup> |
| Payload | One HTTPS URL, built locally by the client application <sup>[5][5]</sup> |
| Hash | SHA-256 of the invoice XML file, Base64URL-encoded (the *wyróżnik faktury*) <sup>[1][1]</sup> <sup>[4][4]</sup> <sup>[5][5]</sup> |
| Date format | `DD-MM-RRRR` (day first) <sup>[5][5]</sup> |
| Version, error correction, print size | Not fixed. The guide's code sample only sets `PixelsPerModule = 5` <sup>[5][5]</sup> |

### Hosts

| Environment | Host |
|---|---|
| TE (test) | `qr-test.ksef.mf.gov.pl` |
| DEMO (pre-production) | `qr-demo.ksef.mf.gov.pl` |
| PROD | `qr.ksef.mf.gov.pl` |

All three are listed in the ministry's guide <sup>[5][5]</sup>.

### KOD I: invoice verification

```
https://{host}/invoice/{seller NIP}/{date DD-MM-RRRR}/{SHA-256 Base64URL}
```

The ministry's published sample, on the test host, uses the dummy NIP `1111111111` <sup>[5][5]</sup>. The ministry's one-page summaries list the same elements <sup>[6][6]</sup> <sup>[7][7]</sup>:

```
https://qr-test.ksef.mf.gov.pl/invoice/1111111111/01-02-2026/UtQp9Gpc51y-u3xApZjIjgkpZ01js-J8KflSPW8WzIE
```

The date is the issue date from field `P_1` of the FA(3) structure <sup>[4][4]</sup> <sup>[5][5]</sup>. The regulation substitutes the correction date on a corrective invoice <sup>[1][1]</sup>. On VAT RR invoices for flat-rate farmers, the farmer's NIP takes the seller's place <sup>[1][1]</sup>. The hash in the sample is 43 characters with no padding, which decodes to 32 bytes.

The text directly under the symbol depends on the invoice's state <sup>[1][1]</sup> <sup>[5][5]</sup>:

| State | Label under KOD I |
|---|---|
| KSeF number assigned | The KSeF number |
| Not yet sent to KSeF | `OFFLINE` |

A KSeF number has 35 characters, `NIP-RRRRMMDD-FFFFFFFFFFFF-FF`: the seller's NIP, the date, 12 uppercase hexadecimal characters, and a CRC-8 checksum (polynomial 0x07, initial value 0x00) <sup>[13][13]</sup>.

### KOD II: certificate verification (offline only)

```
https://{host}/certificate/{context type}/{context value}/{seller NIP}/{certificate serial}/{SHA-256 Base64URL}/{signature Base64URL}
```

- **Context type:** `Nip`, `InternalId`, `NipVatUe` or `PeppolId` <sup>[5][5]</sup> <sup>[14][14]</sup>. The context is the identifier of the taxpayer on whose behalf the issuer is authorised <sup>[1][1]</sup>.
- **Certificate:** an active KSeF certificate of type `Offline`, which the portal calls type 2. An `Authentication` certificate must not be used <sup>[4][4]</sup> <sup>[5][5]</sup> <sup>[12][12]</sup>. Certificates last at most 2 years <sup>[1][1]</sup>.
- **Signed string:** the URL without `https://`, up to and including the hash, with no trailing slash. It is hashed with SHA-256 and then signed <sup>[5][5]</sup>. The ministry's sample on the test host <sup>[5][5]</sup>:

```
qr-test.ksef.mf.gov.pl/certificate/Nip/1111111111/1111111111/01F20A5D352AE590/UtQp9Gpc51y-u3xApZjIjgkpZ01js-J8KflSPW8WzIE
```

- **Signature, RSA:** RSASSA-PSS with SHA-256, MGF1 with SHA-256, a 32-byte salt and a key of at least 2048 bits <sup>[5][5]</sup>.
- **Signature, ECDSA:** P-256 with SHA-256. IEEE P1363 output (R || S) is recommended, with ASN.1 DER only where P1363 is technically impossible <sup>[5][5]</sup>.
- **Encoding:** the signature is Base64URL-encoded, and `CERTYFIKAT` goes directly under the symbol <sup>[1][1]</sup> <sup>[5][5]</sup>.

### Payload length

By arithmetic on the sample values, assuming an unpadded signature as with the hash: on the production host, KOD I is 99 characters. KOD II is about 211 characters with a P-256 signature (86 characters) and about 467 with RSA-2048 (342 characters). An RSA code is therefore much denser, a consequence the guide does not discuss.

### Verification

Scanning needs no KSeF login, only a smartphone <sup>[9][9]</sup>. It is a two-step design:

1. **KOD I.** The scan shows basic identifying data and whether the invoice is in KSeF <sup>[4][4]</sup>.
2. **Full download.** This requires the invoice number, the buyer's identifier (or a statement that there is none) and the gross total <sup>[1][1]</sup>.

For KOD II, the system checks certificate validity, the signature, the issuer's permissions, and consistency between the context and the seller's NIP <sup>[5][5]</sup>.

### Which codes go where

| Invoice | Codes | Legal basis |
|---|---|---|
| Online, or offline already sent to KSeF, used outside KSeF | KOD I + KSeF number | Reg. § 9(1)–(2) <sup>[1][1]</sup> |
| offline24, or offline during unavailability, handed before sending to a buyer listed in art. 106gb(4) | KOD I + `OFFLINE`, and KOD II + `CERTYFIKAT` | Reg. § 9(3), (10) <sup>[1][1]</sup>; art. 106nda(6) <sup>[2][2]</sup> |
| Emergency mode (*awaria*), handed to any buyer before sending | Same two codes | Reg. § 9(4), (10) <sup>[1][1]</sup> |
| Total outage (*awaria całkowita*) | None | KSeF guide <sup>[11][11]</sup> |

The buyers in art. 106gb(4) include foreign buyers, certain EU SME-scheme taxpayers, buyers with no tax number, and consumers <sup>[2][2]</sup> <sup>[3][3]</sup> <sup>[4][4]</sup>. If the invoice format cannot carry a graphic, a separate link or image goes with it, along with the number or label <sup>[1][1]</sup>.

Submission deadlines differ by mode: next working day for offline24 (art. 106nda(2)), next working day after unavailability ends for offline, and 7 working days after the failure ends for emergency mode <sup>[2][2]</sup> <sup>[8][8]</sup> <sup>[11][11]</sup>.

## Use cases

- **Consumer invoices.** Issuing these through KSeF is voluntary, but one that is issued there and handed over by PDF or print must carry the code <sup>[9][9]</sup>.
- **Foreign buyers.** Their invoices carry a QR code and the KSeF number, so they can verify them <sup>[9][9]</sup>.
- **Outage continuity.** Two-code invoices can be handed over while KSeF is down <sup>[10][10]</sup>.
- **Courts and prosecutors.** An e-invoice a taxpayer must provide to them, when used outside KSeF, carries the code and the KSeF number <sup>[10][10]</sup>.
- **Bookkeeping and third parties.** A visualisation can serve as an accounting document if the code allows checking against the source file, and invoices with a KSeF number can be used elsewhere, for example to register a vehicle <sup>[9][9]</sup>.
- **Agriculture.** VAT RR invoices for purchases from flat-rate farmers follow the same marking when used outside KSeF <sup>[1][1]</sup>.

The duty is not limited to the seller: art. 106gb(5a) and art. 106nda(8) also bind any other entity that uses the invoice outside KSeF <sup>[2][2]</sup>.

## Implementations

No dedicated KSeF QR decoder turned up in this research, and the listed libraries are generators. Because the code is a plain URL, a generic QR reader returns the link.

| Project | Lang | Stars | Last active | Notes |
|---|---|---|---|---|
| [CIRFMF/ksef-client-csharp](https://github.com/CIRFMF/ksef-client-csharp) | C# | 115 | 2026-10 | Ministry of Finance library; builds both links, renders and labels the QR <sup>[5][5]</sup> <sup>[23][23]</sup> <sup>[24][24]</sup> |
| [CIRFMF/ksef-client-java](https://github.com/CIRFMF/ksef-client-java) | Java | 49 | 2026-09 | Ministry of Finance library; same functions in Java <sup>[5][5]</sup> <sup>[23][23]</sup> <sup>[25][25]</sup> |
| [smekcio/ksef-client-python](https://github.com/smekcio/ksef-client-python) | Python | 29 | 2026-10 | Third-party SDK; verification links, and PNG output through an optional `qr` extra <sup>[26][26]</sup> |

The normative guide lives in [CIRFMF/ksef-api](https://github.com/CIRFMF/ksef-api) (230 stars), whose offline and certificate chapters sit alongside it <sup>[23][23]</sup>.

## Comparison

- **KSeF QR vs ZBP 2D.** A Polish invoice can carry both. ZBP 2D is a payment order for a banking app, while the KSeF code only verifies the invoice and pays nothing <sup>[22][22]</sup>.
- **KSeF QR vs [ZATCA eInvoice QR](https://docs.barcoder.ai/docs/standards/zatca-einvoice-qr).** A forum copy of the Saudi specification describes Base64-encoded TLV holding the seller, amounts, hash and signature inside the symbol <sup>[21][21]</sup>. KSeF puts only identifiers, a hash and, on KOD II, a signature into a link, and the invoice details stay in the system, so checking a code means going online.
- **KOD I vs KOD II.** KOD I proves a match with a record in KSeF. KOD II covers the period when there is no record yet, by proving who issued the invoice and that it is unchanged <sup>[4][4]</sup>.

## Fun facts

- In October 2023 the open question was how to link a code to a KSeF number that does not exist yet <sup>[19][19]</sup>. The published answer leaves the number out of the link altogether, and prints it only as a label <sup>[5][5]</sup>.
- The KSeF number moves from the printed label to the bank transfer: from 1 January 2027, art. 108g applies to payments and brings it into transfers <sup>[2][2]</sup> <sup>[8][8]</sup>.

## Status

**Active and mandatory where it applies.** The ministry's portal and API documentation were still being updated in October 2026; API version 2.9.0 reached production on 15 October 2026 <sup>[14][14]</sup>.

- **KSeF mandate.** From 1 February 2026 for businesses with 2024 sales above PLN 200 million including VAT, and from 1 April 2026 for the others <sup>[8][8]</sup>. A June 2024 ministry note had planned to count 2025 sales <sup>[15][15]</sup>. Businesses with invoice sales up to PLN 10,000 gross a month may stay outside KSeF until 31 December 2026 <sup>[8][8]</sup>.
- **Penalties.** Art. 106ni allows a fine of up to 100% of the VAT shown, or 18.7% of the gross total where no VAT is shown <sup>[3][3]</sup>. It covers failing to issue in KSeF, issuing against the template during offline periods, and late submission <sup>[2][2]</sup> <sup>[3][3]</sup>. A missing QR code is not listed in the text reviewed.
- **Penalty date.** Enacted law says 1 January 2027 <sup>[2][2]</sup>. Sejm print 3245, dated 20 October 2026, would move it to 1 January 2028, with the act taking effect on 31 December 2026 <sup>[16][16]</sup>. The vendor tracker LookupTax listed it on 28 October 2026 as proposed, with its first reading on 21 October <sup>[17][17]</sup>; the ministry's announcement of 16 September is reported by Firmove <sup>[20][20]</sup>. The Sejm's own process page could not be read, so check before relying on either date.

## Sources

[1]: https://eli.gov.pl/eli/DU/2025/1815/ogl/pol/pdf
[2]: https://eli.gov.pl/eli/DU/2025/1203/ogl/pol/pdf
[3]: https://eli.gov.pl/eli/DU/2023/1598/ogl/pol/pdf
[4]: https://ksef.podatki.gov.pl/informacje-ogolne-ksef-20/kody-weryfikujace-qr/
[5]: https://raw.githubusercontent.com/CIRFMF/ksef-api/main/kody-qr.md
[6]: https://ksef.podatki.gov.pl/media/gx5fihfr/ksef-kod-qr-dla-faktury-wystawionej-online.pdf
[7]: https://ksef.podatki.gov.pl/media/nc4iqf42/ksef-kody-qr-dla-faktury-wystawionej-offline.pdf
[8]: https://ksef.podatki.gov.pl/duze-firmy/
[9]: https://ksef.podatki.gov.pl/pytania-i-odpowiedzi-ksef-20/
[10]: https://ksef.podatki.gov.pl/ksef-news/tryb-offline-i-kody-qr/
[11]: https://raw.githubusercontent.com/CIRFMF/ksef-api/main/tryby-offline.md
[12]: https://raw.githubusercontent.com/CIRFMF/ksef-api/main/certyfikaty-KSeF.md
[13]: https://raw.githubusercontent.com/CIRFMF/ksef-api/main/faktury/numer-ksef.md
[14]: https://raw.githubusercontent.com/CIRFMF/ksef-api/main/api-changelog.md
[15]: https://ksef.podatki.gov.pl/wyjasnienia/obowiazkowy-ksef-odroczony-do-1-lutego-2026-r/
[16]: https://api.sejm.gov.pl/sejm/term10/prints/3245/3245.pdf
[17]: https://lookuptax.com/tax-changes/poland/druk-3245-ksef-penalties-2028-reverse-charge-2030
[18]: https://sovos.com/regulatory-updates/vat/poland-technical-specification-on-qr-codes-has-been-published/
[19]: https://akademialtca.pl/blog/ksef-i-kody-qr-odpowiedz-ministerstwa-finansow
[20]: https://firmove.pl/aktualnosci/biznes/prowadzenie-firmy/news-ksef-bez-kar-do-2028-roku
[21]: https://zatca1.discourse.group/t/structure-of-the-qr-code-for-electronic-tax-invoices/483
[22]: https://docs.barcoder.ai/docs/payments/PL
[23]: https://github.com/CIRFMF/ksef-api
[24]: https://github.com/CIRFMF/ksef-client-csharp
[25]: https://github.com/CIRFMF/ksef-client-java
[26]: https://github.com/smekcio/ksef-client-python

[1] [Rozporządzenie Ministra Finansów i Gospodarki z dnia 12 grudnia 2025 r. w sprawie korzystania z Krajowego Systemu e-Faktur, Dz. U. 2025 poz. 1815](https://eli.gov.pl/eli/DU/2025/1815/ogl/pol/pdf) — Dziennik Ustaw, 2026
[2] [Ustawa z dnia 5 sierpnia 2025 r. o zmianie ustawy o VAT, Dz. U. 2025 poz. 1203](https://eli.gov.pl/eli/DU/2025/1203/ogl/pol/pdf) — Dziennik Ustaw, 2026
[3] [Ustawa z dnia 16 czerwca 2023 r. o zmianie ustawy o VAT, Dz. U. 2023 poz. 1598](https://eli.gov.pl/eli/DU/2023/1598/ogl/pol/pdf) — Dziennik Ustaw, 2026
[4] [Kody weryfikujące QR](https://ksef.podatki.gov.pl/informacje-ogolne-ksef-20/kody-weryfikujace-qr/) — Ministerstwo Finansów, published 30.06.2025, modified 06.02.2026, 2026
[5] [Kody weryfikujące QR (kody-qr.md)](https://raw.githubusercontent.com/CIRFMF/ksef-api/main/kody-qr.md) — KSeF 2.0 API documentation, dated 21.08.2025, 2026
[6] [Kod QR dla faktury wystawionej ONLINE](https://ksef.podatki.gov.pl/media/gx5fihfr/ksef-kod-qr-dla-faktury-wystawionej-online.pdf) — Ministerstwo Finansów, 2026
[7] [Kody QR dla faktury wystawionej OFFLINE](https://ksef.podatki.gov.pl/media/nc4iqf42/ksef-kody-qr-dla-faktury-wystawionej-offline.pdf) — Ministerstwo Finansów, 2026
[8] [Duże firmy](https://ksef.podatki.gov.pl/duze-firmy/) — Ministerstwo Finansów, modified 30.10.2025, 2026
[9] [Pytania i odpowiedzi KSeF 2.0](https://ksef.podatki.gov.pl/pytania-i-odpowiedzi-ksef-20/) — Ministerstwo Finansów, modified 08.10.2026, 2026
[10] [Tryb offline i kody QR](https://ksef.podatki.gov.pl/ksef-news/tryb-offline-i-kody-qr/) — Ministerstwo Finansów, 27.04.2026, 2026
[11] [Tryby offline (tryby-offline.md)](https://raw.githubusercontent.com/CIRFMF/ksef-api/main/tryby-offline.md) — KSeF 2.0 API documentation, 2026
[12] [Certyfikaty KSeF (certyfikaty-KSeF.md)](https://raw.githubusercontent.com/CIRFMF/ksef-api/main/certyfikaty-KSeF.md) — KSeF 2.0 API documentation, 2026
[13] [Numer KSeF (numer-ksef.md)](https://raw.githubusercontent.com/CIRFMF/ksef-api/main/faktury/numer-ksef.md) — KSeF 2.0 API documentation, 2026
[14] [API changelog](https://raw.githubusercontent.com/CIRFMF/ksef-api/main/api-changelog.md) — KSeF 2.0 API documentation, 2026
[15] [Obowiązkowy KSeF odroczony do 1 lutego 2026 r.](https://ksef.podatki.gov.pl/wyjasnienia/obowiazkowy-ksef-odroczony-do-1-lutego-2026-r/) — Ministerstwo Finansów, 11.06.2024, 2026
[16] [Druk nr 3245: rządowy projekt ustawy o zmianie ustawy o VAT](https://api.sejm.gov.pl/sejm/term10/prints/3245/3245.pdf) — Sejm RP, 20.10.2026, 2026
[17] [Druk 3245: KSeF penalties 2028](https://lookuptax.com/tax-changes/poland/druk-3245-ksef-penalties-2028-reverse-charge-2030) — LookupTax (vendor), updated 28.10.2026, 2026
[18] [Poland: technical specification on QR codes has been published](https://sovos.com/regulatory-updates/vat/poland-technical-specification-on-qr-codes-has-been-published/) — Sovos (vendor), 19.12.2023, 2026
[19] [KSeF i kody QR – odpowiedź Ministerstwa Finansów](https://akademialtca.pl/blog/ksef-i-kody-qr-odpowiedz-ministerstwa-finansow) — Akademia LTCA (third party), 13.10.2023, 2026
[20] [KSeF bez kar do 2028 roku](https://firmove.pl/aktualnosci/biznes/prowadzenie-firmy/news-ksef-bez-kar-do-2028-roku) — Firmove.pl (third party), 21.10.2026, 2026
[21] [Structure of the QR code for electronic tax invoices](https://zatca1.discourse.group/t/structure-of-the-qr-code-for-electronic-tax-invoices/483) — Fatoora Developer Community forum, 12.08.2023, 2026
[22] [Poland country report](https://docs.barcoder.ai/docs/payments/PL) — Barcoder research corpus, 2026
[23] [CIRFMF/ksef-api](https://github.com/CIRFMF/ksef-api) — GitHub, 2026
[24] [CIRFMF/ksef-client-csharp](https://github.com/CIRFMF/ksef-client-csharp) — GitHub, 2026
[25] [CIRFMF/ksef-client-java](https://github.com/CIRFMF/ksef-client-java) — GitHub, 2026
[26] [smekcio/ksef-client-python](https://github.com/smekcio/ksef-client-python) — GitHub, 2026

## Deployments

_No country reports mention this standard by name._