KSeF penalties: how high they can be and when they start
Choose the breach and enter the invoice gross amount and VAT. The calculator shows the maximum penalty and whether a penalty applies at all in the year of issue.
Maximum penalty for this invoice
PLN 2,300.00
Up to 100% of the VAT shown on the invoice.
| Current law (from 1 January 2027) | penalty possible |
| Bill, print no. 3245 (from 1 January 2028) | no penalty |
| Payment deadline | 14 days after the decision is served |
Art. 106ni(1) of the VAT Act: a penalty "up to" this amount, imposed by decision of the head of the tax office. The deferral bill was adopted by the Council of Ministers on 20 October 2026 and had its first Sejm reading on 21 October 2026: it is not law yet.
Prepared by Radif Partners · Method · VAT Act, regulations and ministry notices checked on 25 October 2026
Penalties for KSeF errors are set out in Article 106ni of the Polish VAT Act. The head of the tax office may impose a financial penalty for issuing an invoice outside the system despite the obligation, for an invoice in offline or failure mode that does not follow the template, and for failing to send such an invoice to KSeF on time. The maximum is 100 percent of the VAT on the invoice, and where the invoice shows no VAT, for example on exempt sales, 18.7 percent of the total amount due. The penalty is paid within 14 days of the decision being served. Under the current wording of the law the provision applies from 1 January 2027. On 20 October 2026 the Council of Ministers adopted a bill moving that date to 1 January 2028; it is Sejm print no. 3245, after its first reading on 21 October 2026, and not yet law. In 2026 there is therefore no financial penalty for KSeF errors.
The three breaches in Article 106ni
Article 106ni of the VAT Act, added by the Act of 16 June 2023, lists the situations that can lead to a penalty:
| Breach | Maximum penalty |
|---|---|
| invoice issued outside KSeF despite the obligation | 100% of VAT or 18.7% of gross |
| offline or failure-mode invoice not following FA(3) | 100% of VAT or 18.7% of gross |
| offline or failure-mode invoice sent late | 100% of VAT or 18.7% of gross |
For an invoice of PLN 12,300 gross with PLN 2,300 VAT, the ceiling is PLN 2,300.00. For an invoice of PLN 5,000 without VAT: PLN 935.00.
From when: the law and the bill
| Step | Date |
|---|---|
| Ministry notice on extending the postponement | 16 September 2026 |
| Bill adopted by the Council of Ministers | 20 October 2026 |
| First reading, print no. 3245 | 21 October 2026 |
| Penalties under the law in force | 1 January 2027 |
| Penalties under the bill | 1 January 2028 |
The date in the law comes from Article 23(4) of the 2023 Act as worded by the Act of 5 August 2025. You can follow the bill in the Sejm legislative record; the ministry announced the change in its notice of 16 September 2026 and described the government decision in its notice of 20 October 2026.
How to avoid a penalty
The most common cause will be an offline invoice sent late. The deadline depends on the mode and on holidays, so check it straight away:
Send the invoice to KSeF by
Send the invoice to KSeF by
28 December 2026
| Counted from | 23 December 2026 |
| Working days | 1 |
| Days off skipped | 24 December 2026 (Christmas Eve), 25 December 2026 (Christmas Day), 26 December 2026 (Second day of Christmas), 27 December 2026 |
| QR codes when handing it over outside KSeF | two: OFFLINE and CERTIFICATE |
The second cause is an invoice outside KSeF after crossing the PLN 10,000 limit. The third is the template: an offline invoice must use the FA(3) structure and carry QR codes, as explained under offline modes.
What to know before penalties start
A penalty is imposed by decision, not automatically by the system, and concerns a specific invoice. The head of the tax office may set it below the ceiling, and the Tax Ordinance procedure applies, so an appeal is available. Penalty proceeds go to the state budget, and the penalty itself is paid without any request into the tax office account within fourteen days of the decision being served.
A period without penalties does not mean there is no obligation. An invoice issued outside KSeF despite the duty is already issued in breach of the Act, and the buyer may have trouble deducting VAT. So the time before penalties apply is best used to practise offline mode, check your software and decide who in the business watches sending deadlines. If you receive a decision, compare the amount with the ceiling the calculator works out.