KSeF’s current situation
As of now, August 2025, the National e-Invoice System is still a voluntary solution. This means that any taxpayer can issue structured invoices, but can also stay with traditional sales documents. Companies already operating under the National e-Invoice System 1.0 can use the repositories, provided by the Ministry of Finance and available at this address.
And although for a long time – since January 2022 – entrepreneurs were assured that KSeF would become mandatory as early as July 1, 2024, nothing of the sort happened. The Minister of Finance, Andrzej Domanski, officially announced on January 19, 2024, that the mandatory use of the National e-Invoicing System would not come into effect in July or at all in 2024.
Since then, there has been a lot of activity around the System. The Ministry conducted an audit and analyzed the results. It then organized public consultations, decided to rebuild the KSeF architecture and made a number of key decisions. The result of all these actions is the current – and final – effective date of the mandatory National e-Invoice System, marked as version 2.0.
On February 1, 2026 , KSeF 2.0 will become mandatory for large entities, i.e. companies whose revenue in 2025 will exceed PLN 200 million.
Two months later – on April 1, 2026 . – KSeF 2.0 will have to be used by other taxpayers. There is one, rather important, exception to this rule.
The additional transition period will cover micro-entrepreneurs with sales of less than PLN 10,000 gross per month. It will last from April 1 to December 31, 2026. During this time, micro-enterprises will not have to issue invoices in KSeF. The KSeF 2.0 start date for these entities is therefore set for January 1, 2027.
At what stage is KSeF now?
On June 17, 2025 , the Council of Ministers adopted a draft law amending the Law on Value Added Tax and some other laws on the subject of the National e-Invoicing System (KSeF).
On August 27, 2025 , President Karol Nawrocki signed the document. There is no turning back from this decision. KSeF will be mandatory, and soon.
If you want to know what the National e-Invoicing System actually is and how the lives of entrepreneurs will change after its introduction, the answer is below.
What is the National e-Invoicing System all about?
The National e-Invoice System is a solution that allows taxpayers to issue and share structured invoices. They will replace paper and electronic invoices. A structured invoice issued in KSeF will adopt the .xml format. This format – as of today (August 29, 2025) – must comply with the logical structure of the FA(2) e-invoice. Why as of today? Because as a result of public consultations, the Ministry of Finance has decided that the logical structure needs to be updated. The FA(3) structure is expected to come into effect in parallel with the launch of the mandatory KSeF, i.e. on February 1, 2026.
Important!
The FA(3) logical structure became available on June 25, 2025. This means that – if your company is already at this advanced stage of preparation or is actively using the National e-Invoice System – you can already start working on adapting your internal systems to use the new logical structure.
Who can use the KSeF?
In principle, structured invoices in the National e-Invoice System can be issued by almost any business:
- active VAT taxpayers;
- VAT-exempt entrepreneurs;
- Taxpayers identified in Poland for the special EU OSS procedure who have a Polish TIN.
Let’s make it clear: if your company is already ready to adopt KSeF, it can use the System now. All necessary applications – including the KSeF Mobile Application – have already been made available in the production version. This means that entrepreneurs can use them and issue structured invoices without any obstacles.
However, it should be borne in mind that some of the components of the National e-Invoicing System and the legal acts related to its operation (such as the VAT Act) will change in the coming months – in February 2026 at the latest.
How to issue an e-invoice in KSeF in 2025?
A taxpayer can issue a structured invoice using KSeF’s free tools – both the trial, pre-production and production versions of the KSeF Taxpayer Application are currently available. You can access them, as well as the KSeF Mobile Application (note: the latter is only available in the production version) by clicking on this link.
Important!
If you want to see how the KSeF Taxpayer Application works, test its functions, choose the trial version. You can also use a pre-production (demo) version of the application.
If you choose the production version of the Taxpayer Application and issue an invoice in it, it will become a document entered into legal circulation. The production version is therefore the final one. It is already being used by companies that have decided to implement and launch KSeF. Once the mandatory use of the system is in place, all taxpayers will be able to use the KSeF Taxpayer Application to issue structured invoices.
After selecting the appropriate variant of the application, enter your company’s TIN, and then log in with your Trusted Profile or Qualified Certificate.
The next step will be to sign the document with an electronic signature – this will authorize it, and the KSeF system will become available to the taxpayer from now on.
Structure of the e-invoice in KSeF
Before you decide to issue an e-invoice in the KSeF system, remember that the document schema contains three types of fields to be filled in. These are mandatory, optional and optional fields. There are more than 300 fields available in the schema, so we recommend extreme caution and meticulousness, especially when issuing a structured invoice in the National e-Invoice System for the first time.
- The mandatory fields of the e-invoice must be completed regardless of the circumstances. This category includes such information as the data of the seller and buyer, the date of issuance of the document or the date of performance of the service (delivery of goods).
In the context of KSeF, it is worth remembering that negative indications, i.e. information that a circumstance does not exist, should also be introduced in the e-invoice. A value of 1 indicates the presence, while a value of 2 indicates the absence of the circumstance.
In the case of paper invoicing, such action is not required, but in KSeF it is a necessity. Nonetheless, it is expected that this obligation will be reflected in the functionality of the KSeF Taxpayer Application, and it will not be possible to omit such a field when issuing an e-invoice. Importantly, without filling in the mandatory fields, KSeF will not allow the invoice to be sent.
- Optional fields are mandatory to be filled in if a statutory condition is met, i.e. circumstances require it – e.g. the type of invoice issued, or one of the statutory conditions requiring the field to be filled in is met.
It is worth remembering that failure to fill in any of the optional fields is not a technical error, which means that the invoice will be accepted by the system and issued correctly.
However, when this invoice is received by the counterparty and an irregularity is noticed, or the invoice is audited, a corresponding correction will have to be made.
Before sending an e-invoice, review all available fields – especially optional fields – to make sure they need to be filled in.
EXAMPLE
Field P_8B – quantity (number) of goods or range of services – is optional. However, the VAT Law clearly states that it is mandatory for all sales documents except simplified invoices (documenting transactions concluded for up to PLN 450).
It is for this reason that this field has not been marked as mandatory in the system, but failure to fill it out in a standard invoice is tantamount to making a factual error and requires correction.
- Optional fields can be filled in, but this does not in any way affect the correctness of the issued e-invoice. This group of fields includes annotation fields, as well as fields that are not required to be filled in under the VAT Act, but – for example – under other laws. Thus, it may happen that the field – although optional – in the case of a given invoice actually turns out to be mandatory.
The overriding principle to follow when issuing invoices is the principle of extreme caution. This is very important especially when completing optional and optional fields, the failure to complete which will not be noted by the application.
Why hasn’t KSeF been introduced in 2024?
According to Marcin Baj, a tax advisor at LTCA, the capacity of the system as found at the beginning of 2024 was not sufficient. Under these circumstances, Polish entrepreneurs could be put in a situation where they would not be able to issue invoices while being legally obliged to do so.
The next step, after a strong response from the MF, is to commission and conduct an external audit, which is expected to result in a full list of KSeF’s errors and problems. Only after the results of the inspection will it be possible to establish an action plan and an estimated date for implementing the system.
Based on the audit results, we decided to build the system architecture from scratch. The contractor will appoint a team of IT architecture specialists. The work we will carry out will make the system reliable, safe and more functional.
Marcin Loboda, head of the National Tax Administration
For more detailed information, see the official announcement from the Ministry of Finance.
SME spokesman triumphs
For many weeks now, voices have been heard saying that businesses are largely not ready to adopt the National e-Invoicing System. One of the more high-profile ones was the initiative of Poland’s SME ombudsman, Adam Abramowicz, who sent an open letter to the Finance Minister, calling for the introduction of KSeF to be staggered.
We already know that the timetable proposed by Abramovich was not adopted, but the SME spokesman’s main point has been met. We will wait until 2026 for the mandatory KSeF, which is even a bit longer than the SME spokesman had anticipated in his plan.
What does the introduction of the mandatory use of the National e-Invoicing System mean?
Although the preparation period is well under way as of early 2022, still many companies are not ready to implement the system. According to the survey, commissioned by inFaktu, only 42% of Polish entrepreneurs have heard of KSeF at all, and only 11% have begun taking steps to implement the System. These are alarming results – they mean that the vast majority of Polish companies will try to implement KSeF almost at the last minute. At the same time, it should be remembered that implementing KSeF is a complicated process that requires not only commitment and time, but also the resources needed to purchase the right software or train employees.
By extending the deadline for making KSeF mandatory, businesses were given valuable time to plan work and implement the system at a leisurely pace, but as the data shows, most did not take advantage of this opportunity. On the other hand, it is also important to remember the large entities that have already prepared for KSeF implementation, often spending a lot of money.
The ongoing test period from 2022, but also the public consultation conducted in 2024 and the audit that preceded it, have already revealed quite a number of potential problems and ambiguities that the National e-Invoicing System may cause. Which are the most common ones that people who have already had the opportunity to use KSeF point to?
- Invoice verification – making a mistake or errors in an e-invoice can result in the KSeF system rejecting the document. This is especially important when a company sends parcels of invoices. In such an arrangement, even a seemingly trivial mistake can result in the rejection of the entire package of documents.
What’s more, once a structured invoice is sent, once it enters the KSeF system, it cannot be canceled or withdrawn – it will absolutely go for verification. This is why verification of documents before they are sent will become even more crucial than it is today. - Authorizations – many companies will have to decide to give authorizations for KSeF operations to the appropriate people – accountants, administrative staff, etc. In large entities, this will require a well-thought-out strategy.
In the context of inevitable personnel changes over months or years, it will also be necessary to attach the question of authority in KSeF to the procedure for revoking access for those leaving the company. However, the issue of privilege management has been addressed and it is already possible to manage privileges in the KSeF Taxpayer Application. - More data – structured invoices will be able to contain more details. This is due, among other things, to the fact that the European Commission accepted the Finance Ministry’s proposal in its entirety, without its own suggestions or amendments.
Obligation to use KSeF – exceptions during the transition period
From February 1 to July 31, 2026, the Ministry of Finance plans to launch a transition period during which taxpayers will not be required to show the KSeF number of an invoice in sales records.
In addition, the MF’s assumptions included leaving entrepreneurs a protective period, during which the contractual penalties, provided for failure to meet the obligations arising from the entry into force of the KSeF, will not be executed. This information has been confirmed by representatives of the Ministry of Finance – the first penalties will not be imposed until 2027. This is good news for entrepreneurs – especially since there is virtually no more time to implement the System in companies.
All this is because the first API tests are scheduled for September, which gives a rapturous three to four months to introduce KSeF into internal systems. What’s more, the KSeF 2.0 test application is not expected to be ready until November 2025. Thus, it appears that withholding penalties and sanctions until 2027 is not a goodwill gesture to businesses, but rather a necessity, taking into account the current state of technical preparedness of the government side, as well as the statistics of Polish companies’ readiness for the System.
Benefits of KSeF
Despite the problems with the implementation of KSeF and the fact that the current technical state of the system does not allow for its full-scale launch, the Finance Ministry insists that KSeF is needed by Poland and Polish entrepreneurs. The Finance Minister made a clear statement in this regard: “We cannot allow companies to not be able to issue invoices. We cannot allow the situation that was with the Polish order. KSeF is needed for the Polish economy and will be introduced. We need to computerize the economy“.
Although, for obvious reasons, the introduction of the National e-Invoicing System (and especially the prospect of making it mandatory) raises doubts and provokes questions about problems, the system undoubtedly also brings benefits. So how will taxpayers’ lives improve after the introduction of KSeF?
- Ultimately, the system will cover all VAT payers and allow automatic generation of tax returns without filling out a PIT. This means that tax refunds should happen faster, all of which will save taxpayers time and hassle.
- The National e-Invoice System database will allow us to select the recipient of the invoice and give us confidence that the document will go to the right entity.
- KSeF is aligned with standards in the European Union – all invoices structured in the EU are created according to a single template, which will make it easier to invoice foreign contractors.
- The uniform file format (.xml) will also avoid problems related to the reading of electronic invoices by individual entrepreneurs – the standardization of the format will ensure that any company computer can cope with reading the data.
- The e-invoices created in KSeF will be stored in the cloud and protected by data backup. Such invoices cannot get lost or destroyed – so the need to issue duplicate invoices will disappear over time.
Good changes at KSeF
2024 and half of 2025 were spent, among other things, developing and amending the KSeF bill. The law has been enriched with a number of changes, which are generally evaluated positively. What has changed in recent months?
- Entrepreneurs will be able to add attachments to invoices issued in KSeF. This omission was widely commented on, as many companies need to issue invoices with attachments (e.g., those that contain standardized data). The lack of this option was quite an inconvenience – fortunately, the current version of the regulations stipulates that a business will only have to make a notification to the e-Invoice Office in order to use the option to add attachments to invoices.
- KSeF will not cover RR VAT invoices. Invoices for purchases of agricultural products from flat-rate farmers will not have to go to KSeF. There will still be a possibility for those willing to issue them in the System, but this functionality will not be available until April 1, 2026.
Important!
It is up to the flat-rate farmer to decide whether RR VAT invoices are to be issued in KSeF.
- The obligation to provide the KSeF number in payments has been dropped . The change also applies to payments using the split payment mechanism.
- An offline mode will be created, allowing entrepreneurs to issue a structured invoice without access to the network. This is a solution designed to deal with failures and temporary problems with Internet access. It will be the entrepreneur’s responsibility to send the invoice to the System no later than the next business day.
- The latest draft also provides for B2C consumer invoicing.
Fines and penalties – how high and for what?
Although the Ministry of Finance has decided to consider 2026 as a transitional year, and penalties and sanctions will be imposed on companies only from January 2027, we already know the list of violations for which entrepreneurs will face consequences. Companies must avoid:
- Issue invoices in programs that do not meet KSeF requirements,
- issuing invoices that do not comply with the accepted scheme,
- Issuing invoices in the System with a delay.
The most serious violation of obligations will, of course, be the failure to issue an invoice at KSeF.
How high are the penalties for misconduct at KSeF?
Businesses face fines of up to 100% of the amount of tax shown on an invoice issued outside the KSeF for violations of the KSeF Law.
In a situation where the value of the tax is not indicated on the invoice, the penalty can be as high as 18.7% of the total amount due on the invoice.
Once the tax authorities decide to impose a penalty, the taxpayer has 14 days to pay.
Summary
The launch of the National e-Invoice System in the Polish tax system is quite a revolution, with as many opportunities as threats. The testing period for the application, as well as the multi-stage consultation with entrepreneurs, has already ended, as has the work on the new logical structure.
However, any entrepreneur can already use the applications provided by the Ministry of Finance. We are talking about the KSeF Taxpayer Application, the e-microfirma application and the KSeF Mobile Application. However, it is worth noting that the available production versions are fully functional applications, the use of which involves the use of the National e-Invoice System. A document issued in the production version of the KSeF Taxpayer Application is binding and goes into the System. Test versions can be used for testing purposes. All variants of the application are available at this address.
