Krajowy System e-Faktur (KSeF) is an invoice management system developed by the Ministry of Finance in Poland. It is designed for issuing, sending, receiving and storing structured invoices.

The KSeF is intended to facilitate the exchange of invoices between entrepreneurs and enhance tax transparency by allowing the Ministry of Finance to improve tax collection and detect tax fraud.

The KSeF system is mandatory for sole proprietors, companies, VAT groups and local government units; it also applies to entities authorized by these taxpayers, such as accounting firms. Additionally, individuals specified in the ZAW-FA notification (authorized by the taxpayer or an enforcement authority) can use the KSeF system.

We are committed to making the entire process of changing the new invoice distribution model as smooth as possible. We have developed various solutions within eService internal systems to facilitate easy access to invoices.

From February 1, 2026, all invoices issued by eService will be published and available for you in the KSeF system. Each invoice will be formatted as an XML file according to the FA(3) schema specified by the Ministry of Finance.

In addition to the KSeF system, eService will provide invoices in all possible formats on its Portal Klienta platform, which will also be a convenient solution especially in the event of KSeF unavailability or technical issues.

Through the Customer Portal you can download:

• invoices in KSeF format (XML), for use e.g. in the situation of a failure of the KSeF system;
• QR codes for displaying and verifying KSeF invoices;
• visualizations of invoices in PDF format.

From February 1, 2026 entrepreneurs with sales exceeding PLN 200 million in 2024 must start issuing invoices through the KSeF platform.
From this date, all entrepreneurs (regardless of turnover in 2024) must begin downloading their  incoming invoices from KSeF. 

From April 1, 2026  the obligation to issue invoices via KSeF extends to all other entrepreneurs (with turnover below PLN 200 million in 2024).

From 1 January 2027 it will become mandatory to include KSeF number in payment titles (both transfers and direct debits).

You can access KSeF without additional credentials by using a qualified electronic seal or by submitting the ZAW-FA form to authorize specific users.

You can use KSeF through:

a) financial and accounting software, if there are integrated with KSeF (integration via an API);

b) free tools from the Ministry of Finance, available at https://ksef.podatki.gov.pl/ including:

• the KSeF Taxpayer Application, available online, which allows users to use the system, manage KSeF authorizations, tokens and certificates, view invoices and download UPO;
• the KSeF Mobile Application, which allows for convenient and quick issuing and receiving invoices in the system using a smartphone, viewing invoices and creating draft invoices.

The KSeF can also be used through an e-mikrofirma available at the e-Tax Office. By linking an existing account to KSeF, taxpayers can issue and receive invoices in the system and transfer them directly to the VAT register, without the need to manually enter data.

If a company (e.g. a partnership) has a qualified electronic seal containing its NIP (Tax ID), it can use the KSeF based on default ownership rights without notifying the Tax Office. If no such seal exists, the company must submit a ZAW-FA form to designate an authorized individual. This person can then grant further permissions electronically within the system.

To log in, you can use an electronic seal, a trusted profile, a qualified electronic signature, login credentials specific to the KSeF mobile app or e-mikrofirma.

Recovery depends on your login method to the KSeF system, as each login method has its own password recovery method. For example, if you log in using a trusted profile via online banking, you should contact your bank. If your electronic seal or PIN is missing, you should contact your seal provider.

Initial access is assigned to the company. However, once logged in, the company can grant specific permissions to individuals, such as employees or accountants.

Yes, you can manage and grant KSeF access rights for your employees within the system.

Most Polish accounting software providers have already implemented or are currently implementing KSeF integration. Please check if your accounting system already has this functionality. If your system does not have this functionality, contact your software provider. 

For foreign or custom software additional work may be necessary. Technical specifications are available at https://ksef.podatki.gov.pl/,  under the “IT Integrators” tab.

KSeF will be the primary distribution channel and will store invoices for 10 years. Under normal operation, the legal concept of a "duplicate" is replaced by the availability of the original structured invoice in the system. In such cases, the process of generating duplicate invoices will be the same as before the KSeF was introduced. However, in the event of a total KSeF outage, eService maintains the functionality to issue duplicate invoices through our standard channels, the process of generating a duplicate invoice will be the same as before the introduction of KSeF.

We do not anticipate significant changes at eService compared to the before-KSeF system. Invoices will be available in KSeF shortly after issuance, with no expected delays compared to the before-KSeF system.

We do not plan to send additional notifications during the initial months of KSeF implementation. If any such requests arise among our clients, we will respond promptly. We will monitor client feedback and may introduce such a feature if there is a significant demand.

It is a free online tool provided by the Ministry of Finance for issuing and receiving structured invoices. It is ideal for businesses whose accounting software is not yet fully integrated.  The KSeF Mobile Application will also be available from February 1, 2026. More information can be found at ksef.podatki.gov.pl.