Current KSeF 2.0 Implementation Plan in Poland – Deadlines, Requirements and Schedule

Introduction: Understanding KSeF – What you need to know about the upcoming changes

The National e-Invoice System, better known as KSeF, is a revolutionary change in the Polish tax system, introducing the obligation to issue and receive invoices in a structured electronic form via a central government platform. For entrepreneurs operating in Poland, understanding the official implementation plan of this system is crucial to timely preparation for the upcoming changes and ensuring operational compliance.

The Ministry of Finance has presented an updated schedule which assumes a gradual introduction of the obligation KSeF, taking into account the size of the companies and the specifics of their activities. The central element of this transformation is the new version of the system, KSeF 2.0, which aims to streamline invoicing processes, increase the security of economic transactions and tighten the tax system. This article is a detailed discussion of the official implementation plan KSeF, based on the latest information published by the Ministry of Finance (as of April 12, 2025), with particular emphasis on key deadlines, technical requirements and available tools.

When will KSeF be mandatory? Detailed implementation schedule

One of the most frequently asked questions by entrepreneurs is: since when KSeF will become mandatory? The answer is not clear, because the implementation has been divided into stages, covering different groups of taxpayers at different times.

Source: https://www.gov.pl/web/finanse/krajowy-system-e-faktur–plan-wdrozenia

Phases of introducing the KSeF obligation

The process of implementing mandatory KSeF has been carefully planned and spread over time to enable companies to adapt to the new regulations:

1. From February 1, 2026: The first to be obliged to apply KSeF will cover large taxpayers. This definition applies to entrepreneurs whose sales value (including VAT) in 2024 exceeded PLN 200 million. Directing the obligation first to the largest entities allows for testing the system's efficiency under heavy load and gives smaller companies time to prepare.
2. From April 1, 2026: In the second stage, the obligation will be extended to other entrepreneurs, both active VAT payers and those exempt. This phase will cover the vast majority of companies operating on the Polish market.
3. From 1 January 2027: The last group covered by the obligation is the smallest taxpayers, referred to as "digitally excluded". This applies to entities whose transactions are characterized by low amounts - up to PLN 450 for a single invoice and at the same time the total value of sales does not exceed PLN 10,000 per month. This later date is intended to provide additional time for adaptation for the smallest companies, which may encounter greater technological barriers.

Transition period and key additional dates

In addition to the main dates of entry into force of the obligation, the Ministry of Finance has also provided for a transitional period and additional deadlines important for the functioning of the system:

• By the end of 2026: Significant facilities are provided to ease the initial adaptation difficulties. During this period:
  • It will still be possible to issue invoices using cash registers under the current rules.
  • There will be no penalties for any errors related to technical aspects of invoicing by KSeF.
  • Providing an identification number will not be mandatory KSeF invoices when making payments, including under the Split Payment Mechanism (MPP). This extended period without sanctions and additional payment obligations, lasting even after the formal launch of the system for most companies (February/April 2026), demonstrates the administration’s pragmatic approach. It acknowledges potential implementation challenges and seeks to minimize disruption to business operations, giving companies real time to adapt their processes without the risk of immediate financial consequences for certain shortcomings.
• From April 1, 2026: As the obligation applies to most entrepreneurs, the system will also be adapted to handle specific documents, such as: KSeF invoices VAT RR type, documenting the purchase of agricultural products from flat-rate farmers. Launching this functionality in parallel with the main implementation for most companies, but as a separately listed point, may suggest that it is a separate module of the system KSeF 2.0, implemented in stages, which is consistent with the strategy of careful, controlled development of the platform.

Table: Schedule for the implementation of the mandatory KSeF

For clarity, key dates for the introduction of the obligation KSeF are presented in the table below:

Preparing for KSeF 2.0: Key Terms for Technology and Testing

In parallel to setting the dates for the mandatory use of the system, the Ministry of Finance is working intensively on the development of the platform KSeF 2.0 and providing tools and technical specifications that will enable entrepreneurs and software vendors to prepare accordingly.

KSeF 2.0 Tool Release Schedule

The roadmap for delivering key technical features and test environments is as follows:

• June 2025: A key moment for IT departments and software providers. The Ministry of Finance plans to publish a new logical structure of the FA(3) e-invoice (the so-called schema) and full documentation of the programming interface (API) for KSeF 2.0. These materials will be the basis for starting adaptation work in company systems.
• September 30, 2025: From this day onwards the API testing phase will begin KSeF 2.0. Initially, system integrators and large companies will have access to the test environment. This choice of the starting group is not accidental - focusing on entities that potentially generate the largest volume of transactions and have the most complex integration needs allows for early detection and removal of potential problems with the scalability and performance of the system. The aim is to stabilize the key infrastructure before its mass load, which minimizes the risk of technical problems after the official start of the obligation KSeF.
• November 2025: A test version is planned to be made available KSeF 2.0 Taxpayer Application. It will be available to all entrepreneurs, allowing them to familiarize themselves with the interface and functionalities of the system. It should be emphasized that invoices issued in the test environment will not have any legal effects and will not enter into real circulation.
• November 1, 2025: Entrepreneurs will be able to start the process of applying for invoice issuer certificates. They are necessary for authentication in the system, and having them will be particularly important in the context of using the "offline24" emergency mode.
• February 1, 2026: In parallel with the entry into force of the obligation for large taxpayers, the production version of the system will be launched KSeF 2.0. From this date on, it will be possible to issue legally binding KSeF invoices in actual economic turnover.

KSeF Invoices in Practice: Technical Requirements and Available Solutions

Implementation KSeF is associated with the need for technical adaptation on the part of entrepreneurs. The Ministry of Finance foresees various paths of interaction with the system, depending on the scale of activity and the IT infrastructure.

KSeF Integration via API

For medium and large enterprises, as well as companies using advanced ERP systems or dedicated accounting and invoicing software, the basic method of communication with the National e-Invoice System will be the programming interface (API) KSeF 2.0. KSeF Integration using API will enable fully automated sending and receiving KSeF invoices directly from the company systems. The key to this process will be: the publication of API documentation in June 2025 and the possibility of testing integration from September 30, 2025. Our service is already providing REST API interface along with detailed documentation, which is compatible with the currently applicable KSeF (v2) schema, and the PHP client library. In the coming days, we also plan to provide libraries for the following languages: Java and .Net.

Official KSeF applications from the Ministry of Finance

The Ministry of Finance will also provide free tools that will enable the use of KSeF for companies that do not have integrated systems or prefer simpler solutions:

• KSeF 2.0 Taxpayer Application: This will be the main web application (accessible via a web browser) intended for management KSeF invoices. It will enable issuing, receiving, viewing and sharing e-invoices. The test version is to be available in November 2025, and the production version from February 1, 2026. It is a basic solution for smaller entities or as a complementary tool for companies using API.
• KSeF Mobile Application: There will also be a free one available KSeF application for mobile devices (Android and iOS), which will be updated to version 2.0. After authentication using a Trusted Profile, the application will allow for basic invoice management - issuing, viewing and secure sharing. Additionally, it will allow for the creation of lists of contractors and their assigned bank accounts, which can facilitate the invoicing process.

Which KSeF program to choose? Customization of company systems

Regardless of the method you choose to interact with KSeF, entrepreneurs need to review and potentially upgrade their current invoicing and accounting software. Choosing the right one KSeF program, it must be ensured that it will be compatible with the new requirements. Commercial software manufacturers will have to adapt their products to allow direct KSeF integration via API or at least cooperation with KSeF Taxpayer Application (e.g. via data import/export). It is recommended to contact the software vendor as early as possible to obtain information about the plans for adaptation to KSeF 2.0 and the update release schedule.

Authentication and Safe Mode "Offline24"

Using KSeF will require appropriate authentication of the user or system identity. Special invoice issuer certificates will play a key role in this process, especially in the context of automation and ensuring business continuity. The possibility of applying for them will be launched on November 1, 2025. Having such a certificate will be necessary, among others, to use the so-called "offline24" emergency mode. This mode was designed to enable issuing invoices even in the event of temporary unavailability of the central system KSeF. The deliberate planning and implementation of the certificate mechanism and offline mode is an expression of the administration's foresight. It is recognized that central systems may be subject to failures, and providing companies with a legal and technically prepared path to continue invoicing in such situations is crucial to minimizing the operational risk associated with mandatory e-invoicing. Detailed technical requirements for certificates are to be published in the API documentation.

Main goals, benefits and challenges related to the implementation of KSeF

The introduction of the National e-Invoice System is not only a technological change, but above all a strategic initiative aimed at modernizing and streamlining the Polish tax system and economic turnover.

Why KSeF? System Objectives

Main goals of the implementation KSeF, according to information from the Ministry of Finance, include:

• Establishing a general obligation to issue structured e-invoices.
• Simplify and speed up the invoicing process.
• Active support for taxpayers in the process of adapting and using the system.
• Ensuring a high level of security and completeness of invoice data.
• Guaranteed continuity of the invoicing process, regardless of temporary technical problems (offline mode).
• Facilitating invoicing for foreign entities and those without a Tax Identification Number.
• Standardization of the moment of issuing an invoice in KSeF, regardless of the mode (online/offline).
• Enabling invoice management via a free mobile app.
• Optional extension of the possibility of issuing invoices in KSeF also for transactions with consumers (B2C).
• Introducing the ability to attach attachments to e-invoices.
• Tightening the tax system by introducing a presumption of authenticity of the invoice origin KSeF.
• Increasing the transparency of economic transactions.

Potential benefits for taxpayers

Implementation KSeF, despite initial challenges, brings a number of potential benefits for entrepreneurs:

• Possibility of obtaining a VAT refund within a shortened period of 40 days (instead of the standard 60).
• Significant relief in terms of the obligation to store and archive most invoices (they will be stored centrally in KSeF).
• No need to issue duplicate invoices in the event of their loss by the recipient.
• Reduced risk of making formal errors when issuing invoices thanks to a structured format.
• Possibility of quick, automated replacement KSeF invoices between contractors.
• Potential for automatic import of data from purchase invoices into financial and accounting systems.
• Introduction of a uniform, standard invoice format for the entire country.
• No obligation to submit invoices in the form of a JPK_FA file upon request of control authorities (for invoices issued in KSeF).
• Increased security and guaranteed integrity of data contained on invoices.

Challenges and preparation of the company

Implementation KSeF also poses specific challenges for companies:

• The need to adapt or replace current accounting and invoicing systems (selecting the appropriate one) KSeF program).
• The need to carry out KSeF integration via API for larger companies or more complex systems.
• The need to familiarize employees with the new system, its functionalities and operation (e.g. KSeF application).
• Obligation to obtain invoice issuer certificates, especially to ensure emergency operation.
• There may be temporary technical difficulties, especially in the initial period of system operation.
• Dependence on a stable internet connection for online mode (although "offline24" mode provides a failsafe).

This duality – on the one hand, the promise of significant operational and financial benefits (such as faster VAT refunds or automation), and on the other, the need to incur costs for the adaptation of systems and processes – underlines the transformational nature of the KSeF. Successful implementation and reaping the benefits of the system will require companies to overcome initial implementation barriers. Awareness of both of these aspects by the tax administration suggests understanding this relationship.

To meet these challenges, companies should take proactive preparation measures: assess the state of current IT systems, establish a dialogue with software vendors, and plan for a possible KSeF integration, train staff and monitor announcements from the Ministry of Finance regarding the availability of certificates and tools. The Ministry also announces intensive educational and assistance activities before the obligation comes into force. Entrepreneurs can submit their comments on the project by sending them to the address (mailto:sekretariat.PT@mf.gov.pl).

Summary: Key steps and dates to remember on your way to KSeF integration

The implementation of the National e-Invoice System is a complex process, but its schedule and key elements have been clearly defined. Key dates, since when KSeF will be mandatory, then:

• February 1, 2026 for large taxpayers (> PLN 200 million in sales in 2024).
• April 1, 2026 for most other entrepreneurs.
• January 1, 2027 for the smallest, “digitally excluded” taxpayers.

Equally important are the deadlines related to technical preparations:

• June 2025: API documentation and FA(3) schema published for KSeF 2.0.
• September 30, 2025: Start of API testing for integrators and large companies.
• November 2025: Test sharing KSeF Taxpayer Application 2.0 and the ability to apply for issuer certificates.

Entrepreneurs will be able to benefit from KSeF through direct KSeF integration via API or through dedicated tools of the Ministry of Finance: KSeF Taxpayer Application 2.0 (web) and mobile application.

The key to a smooth transition to the new system is proactive planning, following official announcements and appropriate technological and organizational preparation in the company. There is a relatively long time for adaptation, but it is worth starting preparations now to fully use the potential and meet the requirements of the National e-Invoice System.

Source: https://www.gov.pl/web/finanse/krajowy-system-e-faktur–plan-wdrozenia

The ksefapi.pl team