If you are planning to start or have already conducted business in Poland however do not have a registered office or fixed establishment in the country, it is still essential to carefully assess your obligations under the Polish National e-Invoicing System (KSeF). Particular importance should be given to the latest explanatory notes issued by the Ministry of Finance regarding the determination of a fixed establishment (FE) for VAT purposes.

In this article, we explain who is required to use KSeF, when a foreign entity may be covered with the obligation to issue structured e-invoices, and we provide the practical implications of the recently published official guidance.

Who Is Required to Use KSeF?

KSeF is a central IT system enabling the issuance and receipt of structured electronic invoices. Invoices issued through KSeF follow a uniform digital format accepted by the Polish tax authorities and are transmitted directly to the system, where they receive a unique identification number.
The system allows the tax authorities to verify invoices in real time, streamlines invoice circulation, and enhances transparency in tax settlements.

The obligation to use KSeF applies to VAT taxpayers who have:

• a registered office (seat) in Poland, or
• a fixed establishment (FE) in Poland.

The implementation of mandatory KSeF is introduced in stages:

• 1 February 2026 – the obligation arose for large taxpayers whose sales value in 2024 exceeded PLN 200 million,
• 1 April 2026 – the obligation will extend to all remaining taxpayers except for micro-enterpreneurs,
• 1 January 2027 – the obligation will apply to micro-entrepreneurs whose monthly sales do not exceed PLN 10,000.

Are Foreign Entities Subject to KSeF?

According to the Explanatory Notes issued by the Polish Ministry of Finance on 28 January 2026 concerning the determination of a fixed establishment in Poland for the purposes of issuing invoices via KSeF, the obligation is not limited solely to companies having their registered office in Poland.

A foreign entity may be required to issue structured invoices via KSeF if it does not have its registered office in Poland, but has a fixed establishment (FE) in Poland, and FE actively participates in the supply of goods or provision of services.

The purpose of the Explanatory Notes is to clarify the practical application of VAT provisions governing the determination of a fixed establishment for KSeF purposes. The document includes a definition of FE, criteria for its existence, and practical examples referring to various business models.

What is important, if any of the required elements is not met, the obligation to use KSeF basically does not arise.

What Is a Fixed Establishment (FE)?

A fixed establishment is any place other than the registered office that is characterized by:

1. an appropriate structure in terms of human and technical resources,
2. the ability to supply goods or provide services independently,
3. a sufficient degree of stability.

The Explanatory Notes refer to established case law of the Court of Justice of the European Union (CJEU), including the judgments in:

• Cabot Plastics Belgium SA C-232/22,
• Berlin Chemie C-333/20,
• Dong Yang Electronics C-547/18.

These rulings emphasize that the existence of a fixed establishment cannot be assessed solely on the basis of the legal form of the entity, existence of a subsidiary, or the existence of a “permanent establishment” within the meaning of regulations of corporate income tax regulations.

The concept of a fixed establishment for VAT purposes is not identical to the concept of a permanent establishment used for income tax purposes. The existence of the one does not automatically imply the existence of the other.

Key Criteria for the Existence of an FE

In order to acknowledge that a fixed establishment exists, the following conditions must be met simultaneously:

1. Human and Technical Resources

The place in question must have an appropriately organized structure including, for example:

• personnel,
• technical infrastructure,
• equipment,
• IT systems,
• possibly real estate (e.g., an office where management decisions are taken).

The resources must have a real not only a substantive character. When Polish-based resources perform only auxiliary, administrative, or preparatory functions the FE should basically not arise.

If a foreign entity uses personnel of another company but does not exercise effective control or supervision over them, and such personnel is not authorized to negotiate or conclude contracts on the foreign company’s behalf, FE should basically not be deemed to exist.

2. Structure Enabling the Supply of Services

The human and technical resources must form a functioning structure capable of independently carrying out economic activities, including concluding contracts within the scope of ordinary business operations.

The degree of independence from the head office and the actual ability to perform transactions is particularly relevant.

3. Sufficient Degree of Stability

The activity must be continuous and stable rather than occasional or temporary. Indicators of permanence may include:

• long-term contracts,
• stable engagement of resources,
• a lasting organizational structure.

The resources must be available to the taxpayer in a manner comparable to having its own resources at its disposal.

Decisive Factor: Active Participation in Transactions

From the perspective of a foreign taxpayer, the key question is whether the fixed establishment actively participates in the supply of goods or provision of services.

The mere existence of a structure in Poland does not automatically trigger the obligation to use KSeF. What is decisive is the actual involvement of the FE in the relevant transaction.

If the analysis shows that the FE actively participates in the supply or service, the foreign taxpayer will be required to issue structured invoices via KSeF.

What About Receiving Invoices by Foreign Entities?

In the situation when a Polish entrepreneur issues an invoice to a foreign contractor, the invoice must be submitted to KSeF, regardless of whether the customer is established within or outside the European Union.

At the same time, the Polish taxpayer must provide the invoice to the foreign contractor in an agreed format, such as:

• by email in PDF format,
• in paper form,
• as a visual representation containing a QR code or a link enabling the invoice to be downloaded from the system.

The Explanatory Notes also clarify that Polish taxpayers acquiring goods or services from foreign contractors are not obliged to assess whether the foreign entity has a fixed establishment in Poland for KSeF purposes.

Broader Tax Implications

Recognition of a fixed establishment in Poland may have consequences not only for KSeF obligations but also in other tax areas, including:

• corporate income tax,
• real estate tax,
• other public levies in Poland.

The published Explanatory Notes demonstrate that the implementation of KSeF may require multinational groups to conduct an internal review of their operating model, the scope of personnel competencies, and the actual involvement of Polish-based structures in transactions. Beyond technical KSeF implementation, other compliance obligations may force  restructuring or clarification of internal processes model within the group.

Summary

The obligation to use KSeF applies to:

• entities having their registered office in Poland, and
• foreign entities having a fixed establishment in Poland that actively participates in supplies of goods or services.

Foreign entities that do not meet the criteria are not required to register in the system or issue structured invoices and will act solely as recipients of invoices issued by Polish suppliers.

Each business model should, however, be overview individually from the perspective of provided criteria and obligations. In cases of doubt, applying for an individual tax ruling may significantly reduce the risk of disputes with the Polish tax authorities.

If you consider VAT registration in Poland or are concerned that the absence of a fixed establishment could be challenged by the Polish tax authorities, we would be happy to assist you.

Our experts provide support in obtaining advance tax rulings as well as comprehensive VAT compliance services in Poland. We will analyse your situation and help you conduct business safely and in full compliance with Polish regulations.

We Invite you to contact us.