KSeF - revolutionary changes in e-invoicing adopted by the government
KSeF - key changes and their significance for business
Intensive work is underway to implement the National e-Invoicing System (KSeF), which will revolutionize the way of invoicing in Poland. The government has adopted key changes to the schedule and scope of the mandatory KSeF, aimed at streamlining the process and enabling entrepreneurs to prepare for the new regulations. Below we present the most important conclusions from the draft amendment to the KSeF adopted by the Council of Ministers.
Two stages of KSeF implementation
The implementation of the National e-Invoicing System will take place in two stages, adjusted to the size of companies and their turnover.
- February 1, 2026 - large companies
The new obligation to invoice in the KSeF will first apply to companies whose annual turnover exceeded PLN 200 million in 2025. These are mainly listed companies, concerns and large capital groups.
- April 1, 2026 - other companies
The remaining VAT payers - i.e. small, medium and most micro-enterprises - will start issuing invoices in the KSeF from April 2026. This postponement by several months compared to previous assumptions is intended to give companies time for technical and organizational preparations.
"Offline24" mode - invoices without internet access
In the new KSeF functioning model, the government has introduced a significant convenience for entrepreneurs in the form of an emergency mode "offline24" . Thanks to it, companies will be able to issue invoices even when the National e-Invoicing System is temporarily unavailable or when for some reason there is no internet access. The key condition for such action is to issue an invoice in accordance with the logical structure of e-invoices (XML) and send such an invoice to KSeF no later than the next business day.
The solution is a direct response to numerous requests submitted by companies operating in field industries, such as transport, construction or service services, where constant and uninterrupted access to the network can be problematic. It is intended to ensure operational continuity and minimize the risk of downtime in issuing sales documents, which is extremely important for financial liquidity and timely settlements.
Possibility to attach documents to the invoice
The amendment to the regulations concerning the National e-Invoicing System (KSeF) introduces a long-awaited functionality: the ability to add attachments to structured invoices. This is a significant improvement that meets the needs of many industries in which attaching additional documents to invoices is standard. This is of particular importance for sectors such as:
- Energy, where invoices are often accompanied by detailed consumption specifications, meter readings or installation acceptance protocols.
- Gastronomy, where it may be necessary to attach confirmations of catering orders, detailed menus or event service contracts.
- Pharmacy, where product quality certificates, laboratory test reports or drug storage conditions can be sent along with the invoice.
- Logistics, where it is necessary to attach bills of lading, confirmations of receipt of goods, transport damage reports or detailed lists of delivered shipments.
Thanks to this function, entrepreneurs will gain the ability to comprehensively document transactions within a single system, which will streamline document circulation, reduce the need to send additional e-mails or paper attachments, and facilitate archiving and access to full commercial documentation.
KSeF – what reliefs and facilities for entrepreneurs?
The aim of KSeF is to streamline processes, increase transparency of transactions and combat tax fraud. However, many entrepreneurs wonder what specific benefits and facilities the implementation of this system brings. Let us take a closer look at what reliefs and facilities await companies in connection with KSeF.
Shortening the VAT refund deadline
Thanks to the draft amendment, VAT will be refundable not in 60, but in 40 days. This is a significant change that improves the financial liquidity of many companies, especially in the SME sector.
Transition period and no penalties
There will be a transitional period until the end of 2026 – without penalties for errors related to the KSeF number on transfers. Importantly, it will still be possible to issue simplified invoices up to PLN 450 from cash registers – until the end of this period.
When does the mandatory KSeF start? Get to know the implementation schedule
The National e-Invoicing System (KSeF) is a significant change for Polish entrepreneurs. It is worth knowing the key implementation dates to properly prepare for the upcoming obligations.
- June 2025 – this is an important month because this is when the new logical structure of e-invoices FA(3) and API KSeF 2.0 are to be published. This is a key moment for IT companies and IT departments that will be able to start integrating their systems with the new version of KSeF.
- September 2025 – the start of open tests of the API environment is planned. Entrepreneurs and software providers will have the opportunity to evaluate the system's operation in conditions close to real ones, which will allow for early detection of potential problems and their elimination.
- November 2025 – according to the schedule, in November the test Taxpayer Application and so-called offline certificates are to be made available. This is another opportunity to get acquainted with the functionalities of KSeF in practice, which is extremely important for smaller companies that can use ready-made solutions.
- Q4 2025 – tests of invoice attachments and consumer invoice handling functions are planned for this period. This means that the system will be evaluated for more advanced functions, which is important for companies with complex operations.
- February 1, 2026 – this is the date from which KSeF will become mandatory for companies with turnover exceeding PLN 200 million. The largest business entities will have to be the first to switch to electronic invoicing, which is to give them additional time to adapt.
- April 1, 2026 – from this day, KSeF will be mandatory for other entrepreneurs, i.e. most companies operating in Poland. Regardless of the size of turnover, everyone will have to issue and receive structured invoices via the KSeF system.
This timeline shows that businesses still have some time to prepare for the changes, but it is crucial to track progress and start adapting early. Is your company ready for KSeF?
How to prepare your company for KSeF? Key steps
The introduction of the National e-Invoicing System (KSeF) is an inevitable change that requires proper preparation on the part of every entrepreneur. It is not worth waiting until the last minute - the sooner a company starts adapting, the smoother the transition to the new system will be. Here are the key actions you should take now:
- Plan and execute testing. Actively participate in available API tests and the KSeF test application. This is a unique opportunity to identify potential issues at an early stage and ensure that your systems are compatible with new requirements. This will avoid surprises when the system becomes mandatory.
- Update your IT systems. Focus on adapting your invoicing software to the FA(3) structure, which is standard in KSeF. Also remember to include support for attachments, which will become an integral part of some invoices. Many ERP systems and accounting programs require appropriate updates - check if your software provider has ready-made solutions.
- Train your team. This is the key to success. Prepare your accounting, sales and payments departments for new procedures related to issuing, receiving and archiving invoices in KSeF. Make sure that all employees understand the principles of the system, can use its functions and know how to proceed in the event of any problems. Good training will minimize the risk of errors and streamline daily operations.
- Secure offline access. Remember that even the most advanced systems can experience failures. Therefore, be sure to prepare offline emergency procedures that will allow you to issue invoices in situations where KSeF is unavailable. Provide your employees with clear instructions on how to proceed in such cases to maintain business continuity.
In summary, KSeF with new functions and reliefs is a significant change that will not only be mandatory, but also more functional and flexible. The coming months are a key time for adaptation so that 2026 does not bring surprises to either the accounting department or business owners. The success of KSeF implementation will depend on effective system integration, comprehensive employee training and preparation of emergency procedures in offline mode.
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