With the KSeF system (Krajowy System e-Faktur), Poland is introducing a national system for electronic invoicing that will have a significant impact on companies. In order to reduce the VAT gap, Poland has acted decisively and strictly - even more decisively than many other countries. The success of these measures will be seen in the future. This is because companies will only have to process every transaction that requires an invoice under Polish VAT law via KSeF from the start of 2026. But what does this mean for German companies?

KSeF and the Polish eInvoice launch

Especially since the introduction of the KSeF system (Krajowy System e-Faktur), e-invoicing has also become increasingly important in Poland. The central platform has been available on a voluntary basis since January 2022 and enables electronic invoices to be issued, received and saved.

It was originally planned that all taxpayers would have to use the KSeF system from July 2024. However, the Polish Ministry of Finance (“Ministerstwo Finansów”) has now announced that the obligation to use electronic invoicing will not be introduced until 2026.

What you should know about electronic invoicing in Poland

While eInvoicing has already found its way into the Polish public administration sector, the introduction process for companies is still in full swing.

eInvoicing in the B2G area

Since April 1, 2019, Poland has had its own online portal, the “Platformy Elektronicznego Fakturowania” (PeF), for the transmission of e-invoices between private companies and public bodies. PeF acts as a Peppol Access Point, which means it is seamlessly integrated into the Peppol network and enables the secure exchange of e-invoices via this Europe-wide network.

Since April 18, 2019, all public institutions must register on this platform and be able to receive structured electronic invoices. There are currently no special requirements for sending and receiving.

Incidentally, Poland has not developed its own national Core Invoice Usage Specification (CIUS). Instead, the standard format based on EN16931 and Peppol BIS Billing 3.0 is used. The eInvoice or CTC (Continuous Transaction Controls) model, which obliges public authorities to send and receive electronic invoices, is centralized in Poland. An electronic signature is not mandatory.

Another important detail is the archiving obligation: Poland requires invoices to be stored for at least five years in either PDF or XML format. Archiving abroad is also permitted under certain conditions.

eInvoicing in the B2B sector

Originally, the mandatory national system for electronic invoicing was to be introduced on July 1, 2024. However, at the beginning of the year, the Minister of Finance postponed this date due to technical problems.

The Polish KSeF system is now to be introduced in two phases from 2026 instead: From February 1, 2026, the obligation will apply to large companies with an annual turnover of over 200 million Polish złoty. From April 1, 2026, the obligation will apply to all other taxable companies.

However, the obligation only applies to the transmission, but not to the receipt of electronic invoice documents. Consent to receive e-invoices is also still required until 2026. However, suppliers in public procurement may continue to use the existing PeF platform if they wish. And: Transactions between companies and consumers (B2C) are exempt from the obligation to issue electronic invoices via KSeF. Nevertheless, companies are given the option of issuing consumer invoices via the KSeF system on a voluntary basis.

Invoices issued in the KSeF must be in XML format, which corresponds to the logical structure FA(2). Depending on the size of the company, the scope of business, and the IT systems used, the invoices can either be created using an application provided by the Polish tax authorities (suitable for companies with few sales documents) or with commercial tools (such as various types of connectors, interfaces, and adaptations to existing software).

As in the field of public administration, the invoicing or CTC model is centralized for companies as well. An electronic signature is also not required in this case.

However, there is a small change regarding the retention period: purchase and sales invoices are stored in the KSeF for ten years, even though the tax limitation period in Poland is actually only five years.

Starting in 2026, all VAT-registered entities with a business address in Poland, as well as all foreign companies with a permanent establishment in Poland, will be subject to the following:

The use of the KSeF system will become mandatory!

One of the biggest challenges for German companies in this process lies in adapting their systems to meet Polish requirements. The KSeF system and the required formats are specific and demand careful integration.

For foreign companies that are only VAT-registered in Poland, the use of the KSeF system remains voluntary, provided they do not have a permanent establishment in Poland or the establishment is not involved in the respective business activities.

Our Tip: Since Polish regulations do not provide a specific definition of a permanent establishment and rely on the EU definition and the case law of the European Court of Justice (ECJ), foreign companies should obtain a binding ruling from the tax authority.

For some foreign companies without a permanent establishment in Poland, using the KSeF system could still be advantageous. Polish companies might prefer suppliers who provide invoices through the KSeF system—especially for domestic goods deliveries subject to Polish VAT.