KSeF – What penalties do businesses face and how can they effectively avoid them?
Incorrect invoice issuance, the absence of contingency procedures, or failure to comply with KSeF-related obligations may lead not only to tax audits but also to fiscal penal liability.
In this article, you will learn:
- What penalties for failure to use KSeF may be imposed on a business?
- From when do administrative sanctions apply?
- Are there any real fines in 2026?
- Which KSeF errors carry the greatest risk?
- How can a company prepare for KSeF and avoid tax-related issues?
Mandatory KSeF from 2026 – What does it mean for businesses?
From 1 April 2026, businesses are required to issue structured invoices via KSeF. In practice, this means adapting accounting systems, procedures, and the organisation of finance department operations. It is worth remembering, however, that the sanctions regime has been introduced gradually.
2026 as a transitional period
Administrative financial penalties under the VAT Act are to be applied only from 1 January 2027. Companies have therefore been given additional time to implement KSeF, test processes, train employees, and prepare contingency procedures. This does not, however, mean a complete absence of risk. As early as 2026, a business may incur liability under the provisions of the Fiscal Penal Code.
Fiscal penal liability in KSeF – risk already from 2026
Many businesses mistakenly assume that because administrative penalties will only apply from 2027, earlier errors will remain without consequences. However, from the moment mandatory KSeF comes into force, the provisions of the Fiscal Penal Code concerning invoicing irregularities will apply.
This means that tax authorities may respond to more serious breaches even before the full administrative sanctions regime comes into effect.
What actions may result in fiscal penal liability?
The risk of liability may arise, among others, in the case of:
- failure to issue an invoice despite the obligation to do so,
- issuing invoices that do not comply with regulations,
- issuing invoices containing information inconsistent with reality,
- refusing to provide an invoice to a contractor,
- using fictitious documents,
- failure to retain the required documentation.
In practice, it will be particularly important to demonstrate whether the business acted in good faith and exercised due diligence.
How high can the fines be?
The amount of fiscal penal penalties depends on the type and scale of the infringement. The regulations provide for:
- up to 180 daily penalty rates for failure to issue an invoice or for issuing a defective invoice,
- up to 720 daily penalty rates for unreliable invoicing or the use of fictitious documents.
Cases involving unreliable invoicing and the use of fictitious documents are treated particularly severely. In the most serious situations, the regulations also provide for the possibility of a custodial sentence. In such cases, liability applies to specific individuals responsible for settlements, including owners, management board members, and accounting staff.
Penalties for failure to use KSeF from 2027 – How much can they amount to?
From 2027, tax offices will be able to impose administrative financial penalties for breaches of obligations related to KSeF.
The sanctions may amount to:
- up to 100% of the VAT amount shown on an invoice issued outside KSeF,
- up to 18.7% of the total amount due where the invoice does not include VAT.
This means that invoicing errors may generate significant costs for a business. For example, an invoice issued outside KSeF for PLN 50,000 net plus PLN 11,500 VAT may result in a penalty of up to PLN 11,500, while a VAT-exempt invoice for PLN 20,000 may result in a sanction of up to PLN 3,740. It is worth remembering that a penalty may be imposed separately for each invoice.
Does every KSeF error result in liability?
No. Tax authorities are expected to distinguish between isolated technical errors and implementation issues on the one hand, and deliberate actions or persistent disregard of obligations on the other. The Ministry of Finance emphasises that 2026 is intended as an adaptation period. This means that isolated technical errors are unlikely to result in severe sanctions.
KSeF and offline mode – How to avoid problems during system failures?
The regulations provide for situations in which issuing an invoice in KSeF is not possible. Businesses may then use various contingency modes, such as offline24, KSeF unavailability mode, system failure mode, or complete failure mode announced by the Ministry of Finance.
In practice, this means that an invoice may be issued temporarily outside the system and then submitted to KSeF within the statutory deadline.
Corrective actions following KSeF errors – What should be done?
In the event of technical issues or invoice errors, a prompt response by the business is crucial. Tax authorities will take into account not only the infringement itself, but also whether the company took corrective action and exercised due diligence. Therefore, in the event of problems with submitting an invoice to KSeF, it is advisable to:
- correct the erroneous document,
- resubmit the invoice to the system,
- document the cause of the technical issue or system failure,
- retain internal evidence of the corrective actions taken.
The regulations provide specific deadlines for completing documentation following technical issues. A business should submit the correct invoice to KSeF:
- within 7 working days after the end of a system failure,
- no later than the next working day after issuing the document in the case of temporary technical issues,
- without undue delay after detecting errors requiring correction of the invoice.
How to avoid KSeF penalties? Recommended actions for businesses
The best protection against sanctions is proper organisational preparation before the full sanctions regime comes into force. We recommend, among other things:
Summary – 2026 is the last opportunity for a safe KSeF implementation
The year 2026 is a transitional period that gives businesses time to implement KSeF calmly and organise their invoicing processes. From 2027, financial sanctions may be very severe and may amount to as much as 100% of the VAT amount shown on an invoice issued contrary to the regulations.
Companies that implement appropriate procedures now, train employees, prepare contingency scenarios, and adapt their accounting systems will significantly reduce the risk of audits, penalties, and tax-related issues. Explore the service: KSeF Consulting in Poland
Do You need support with KSeF implementation?
We help businesses safely prepare their organisations for mandatory KSeF. Contact us and find out how to prepare your company for KSeF without the risk of costly mistakes.
FAQ – The Most Frequently Asked Questions about KSeF Penalties
Administrative financial penalties are expected to apply from 2027. However, liability under the Fiscal Penal Code may still arise.
Breaches of e-invoicing regulations are subject to administrative sanctions. Penalties provided for in the Fiscal Penal Code are imposed on natural persons who commit prohibited acts specified in the Code, including defective or unreliable invoice issuance. Therefore, a company may be penalised for breaching KSeF regulations, while at the same time an employee may be penalised for issuing a defective or unreliable invoice. It should be emphasised, however, that a breach of e-invoicing regulations itself is subject only to the administrative penalties provided for in the VAT Act.
From 2027, the penalty may amount to up to 100% of the VAT shown on the invoice or up to 18.7% of the gross amount due.
It depends on the nature of the error. Tax authorities are expected to take into account the circumstances of the infringement and the scale of the error.
Yes. The regulations provide for special offline modes that allow the invoice to be submitted to the system at a later stage.
As a rule, the Head of the Tax Office imposes an administrative penalty when a breach of KSeF regulations is identified. Tax authorities are required to take into account the scale of the infringement, the circumstances of the error, the actions taken by the company, and the degree of diligence exercised by the business.
A one-off technical issue should not result in the maximum sanction. The risk is greater for companies that have not implemented procedures or that persistently ignore their obligations related to KSeF.
