The National e-Invoicing System (KSeF) is the Ministry of Finance’s central platform for issuing and sharing structured invoices, i.e., e-invoices in XML format compliant with a defined logical structure. The system was created as part of the digitalization of tax settlements, aiming to simplify invoicing for companies and tighten the VAT system.
Below is a detailed chronology of KSeF’s development, key legislative changes, the current and planned implementation schedule, the main challenges, and system functionalities – both existing and planned. All information is based on official sources from podatki.gov.pl and communications from the Ministry of Finance.
National e-Invoicing System – development timeline
The origin of the idea and the pilot phase
The idea for creating KSeF emerged in 2021 as part of work on the SLIM VAT 2 package. The Ministry of Finance, drawing on the experiences of countries like Italy, Spain, and Portugal, decided to implement a nationwide e-invoicing system.
In June 2021, public consultations on the draft law introducing KSeF were completed. By October 2021, a pilot program was launched involving selected taxpayers, which lasted until the end of the year. This allowed for system testing before opening it to all interested parties.
Start of voluntary KSeF use
At the beginning of 2022, under an amendment to the VAT Act, KSeF was made available to taxpayers on a voluntary basis. This meant the ability to issue structured invoices alongside existing formats (paper or PDF). As an incentive, benefits such as shortening the VAT refund period from 60 to 40 days for KSeF users were introduced.
Legislative changes in the implementation process
To enable the use of the system, appropriate legal frameworks had to be established. In October 2021, an amendment to the VAT Act introduced the definition of a structured invoice and outlined system operating principles.
The next step was obtaining EU Council approval for a derogation from the VAT Directive, allowing Poland to introduce mandatory e-invoicing ahead of a pan-European solution. This approval was granted on June 17, 2022.
Based on this, in June 2023, legislation mandating KSeF use was adopted, originally scheduled for mid-2024. However, after analyzing the state of readiness and the results of an IT audit, in January 2024 the Ministry of Finance announced a postponement.
The current legal basis for KSeF is the amendment to the VAT Act from June 2024, which officially deferred the mandatory implementation date.
National e-Invoicing System implementation timeline – from plans to reality
The initial schedule included:
- July 1, 2024 – mandatory use for large and medium-sized enterprises
- January 1, 2025 – mandatory use for VAT-exempt taxpayers
However, after an audit and consultations with businesses, the Ministry of Finance decided to revise the timeline. The updated schedule is as follows:
- February 1, 2026 – mandatory KSeF for large enterprises (revenue over PLN 200 million)
- April 1, 2026 – obligation extended to other taxpayers
- January 1, 2027 – additional time for digitally excluded micro-enterprises
Final deadlines are still subject to change – it is recommended to monitor updates from the Ministry of Finance in the KSeF news section.
National e-Invoicing System – challenges and controversies
The implementation of KSeF proved more complex than originally anticipated. In January 2024, issues with system performance and stability were identified. As a result, an external IT audit was conducted, confirming the need for improvements and infrastructure upgrades.
One of the biggest challenges was market adaptation – both software providers and businesses needed to adjust to the new requirements, including proper training. The Ministry of Finance organized a consultation series titled “Let’s Consult KSeF”, addressing various concerns such as:
- lack of readiness among some taxpayers
- unclear invoice numbering rules
- procedures in case of KSeF system failure
- requirement to include the KSeF invoice number in the payment title (eventually postponed to August 2026)
There were also questions regarding consumer (B2C) invoices. The plan is to allow, but not require, such invoices to be issued via KSeF.
KSeF 2.0 – planned changes and new functionalities
With the postponement of the mandatory implementation date, the Ministry announced the development of a new version of the system, referred to as KSeF 2.0. This includes:
- publication of the final FA(3) invoice structure in mid-2025
- release of a new KSeF 2.0 API in test environments
- open integration tests for software vendors and taxpayers
- launch of a new application for taxpayers with a simplified interface and extended functionality
Improvements are also being considered for local governments (JST), businesses operating in agriculture (VAT RR invoices), and micro-enterprises. The Ministry emphasizes that the system will be tailored to various taxpayer groups and provide a user-friendly experience.
Summary
The National e-Invoicing System is a project of strategic importance for the Polish economy. Implementing mandatory e-invoicing is expected to bring benefits such as process automation, tighter VAT control, and improved economic transaction security.
At the same time, due to the scale of the project and encountered issues, the Ministry of Finance opted to postpone the implementation date and introduce additional facilitations, such as phased rollout, offline24 mode, and the deferral of some formal requirements.
The latest information on KSeF implementation is available on podatki.gov.pl in the KSeF section.
