In 2026, the National e-Invoicing System (KSeF) in Poland became an important part of day-to-day business operations. However, obtaining access to the system is only the first step. Businesses still need to decide who should have access to invoices, how the company will authenticate itself, and how to assign permissions to employees or an accounting firm.
That is why logging in to KSeF should be viewed in practical terms. For business owners, the key issue is not only the authentication method itself, but also how access to the system and document workflows are organised within the company. In practice, this is where many problems arise, especially in companies with a more complex structure or where invoices are handled by more than one person.
Where to log in to the National e-Invoicing System (KSeF)?
The main browser-based access point to the National e-Invoicing System in Poland is the KSeF Taxpayer Application 2.0, a free official tool made available by the Ministry of Finance. It allows users to issue, receive and review structured invoices in line with KSeF requirements. Depending on the level of authorisation, users can also manage permissions and perform additional tasks related to document handling in the system.
In practice, the KSeF Taxpayer Application 2.0 is the main entry point for entrepreneurs who want to use the system directly via the Ministry of Finance website. At the same time, the Ministry also provides other KSeF-related tools, and some functions may be available outside the standard user panel.
For some smaller businesses, the Ministry’s application may be sufficient for day-to-day invoice handling. In larger organisations, it will often operate alongside a finance and accounting system integrated with the KSeF 2.0 API, as part of a wider accounting and document workflow. The Ministry of Finance expressly states that the KSeF Taxpayer Application 2.0 can serve as an alternative to commercial invoicing software, but in practice the right model should be aligned with the size of the business and the way it operates.
From a practical business perspective, it is therefore important to establish early on who in the organisation will use KSeF and to what extent. This may include only the owner, a management board member or another person authorised to represent the company, but also finance staff, administration teams or an external accounting office. This decision affects not only the internal workflow in KSeF, but also the scope of permissions required and the way the system should be implemented.
What authentication methods are available for KSeF
KSeF in Poland does not use a standard username-and-password model. Instead, it relies on authentication methods that confirm the identity of the user or their right to act on behalf of a particular entity. In practice, access to the system depends on the type of taxpayer, the legal form of the business, the rules of representation and whether the user works directly in the KSeF Taxpayer Application or through integrated accounting software.
Trusted Profile and login via login.gov.pl
This option is particularly convenient for natural persons, including sole traders. Following KSeF integration with Poland’s national electronic identification gateway, users can authenticate not only with a Trusted Profile, but also via the mObywatel app, an e-ID card and mojeID through online banking. In practice, after entering the correct tax identification number (Tax Identification Number (NIP)) and completing the authentication process, the entrepreneur gains access to the system without creating a separate username and password. This is often the simplest route for a first login and for ongoing work in the KSeF Taxpayer Application 2.0.
It is worth noting, however, that this method works best when the system is used by a specific natural person acting on their own behalf or as a person authorised to act for an entity. In a more complex organisational structure, authentication of one individual does not automatically solve the issue of granting permissions to employees, in-house accounting staff or an external accounting firm.
Qualified electronic signature
A qualified electronic signature is one of the basic authentication methods in KSeF. It can be used by natural persons who need to confirm their identity in the system in accordance with Ministry of Finance requirements. This is relevant both for entrepreneurs acting personally and for individuals representing business entities, provided that their representation rights and permissions allow them to operate in KSeF.
From a practical perspective, a qualified signature may be especially useful if the entrepreneur wants to use electronic administrative tools not only in KSeF, but also for other business formalities in Poland.
As getsix®, we provide comprehensive support in obtaining a qualified electronic signature in cooperation with one of Poland’s leading trust service providers. Contact us.
Qualified electronic seal
A qualified electronic seal is particularly important for companies and other entities that are not natural persons. Unlike a qualified electronic signature, which is linked to a specific individual, a qualified seal is linked to the organisation itself. For that reason, it may be the right solution where KSeF access needs to be organised at company level rather than being based solely on one individual user.
In practice, this method can make access management easier in larger entities, especially where KSeF is connected to accounting processes and internal document workflows. Even so, using a qualified seal does not eliminate the need to properly define user roles and permissions within the company.
KSeF certificate and token
A KSeF certificate and token are used primarily in system integration environments and for automated communication with KSeF. They should not be confused with an ordinary user login to the browser-based panel. The Ministry of Finance explains that, in order to apply for a KSeF certificate, the user must first authenticate in the system as a taxpayer or an authorised person, for example using a Trusted Profile, a qualified electronic signature or a qualified electronic seal. This means that the certificate does not replace the initial confirmation of identity or authorisation, but serves as an additional tool used at a later stage of working with the system.
This distinction matters, because many implementation mistakes happen at this exact point. Tokens and certificates are mainly intended for system-to-system communication, not for standard manual login in the KSeF Taxpayer Application. The official KSeF portal also indicates that, from 1 January 2027, the target model is for certificates to remain as the long-term technical solution, which is important for businesses planning durable system integration.
How to log in to the National e-Invoicing System (KSeF) as a sole trader in Poland
For a sole proprietorship in Poland, access to KSeF is usually simpler than in the case of companies. The entrepreneur acts in their own name, so after opening the KSeF Taxpayer Application, they indicate the business NIP, choose the authentication method and complete the login process.
At this stage, many business owners assume the matter is closed. In practice, this is sufficient only if the owner handles invoices personally. If document handling is to involve an employee, an administrative staff member, an accountant or an external accounting firm, the business must also ensure that permissions are granted correctly.
How to obtain access to KSeF in a company
For companies, the procedure is more demanding because the rules of representation and the legal basis on which a specific person gains access to the system must be taken into account. In some cases, authentication via a qualified electronic seal or qualified electronic signature will be possible. In others, it may be necessary to file the Notification of granting or revoking authorisations to use KSeF (ZAW-FA) first. Official Ministry guidance confirms that this notification is necessary for entities that are not natural persons and cannot authenticate electronically, for example companies that do not have a qualified seal. In February 2026, the Ministry also announced the availability of ZAW-FA (3) in the e-Tax Office system.
This stage is often the source of practical problems. If a company waits too long to formally designate the person who should obtain initial access to KSeF, it may find that technical login options exist, but the organisation is still not ready to handle invoices on an ongoing basis.
For companies in Poland, it is worth deciding in advance:
- who should obtain first access to KSeF,
- who will manage permissions,
- who will issue invoices,
- who will receive purchase invoices and cost documents,
- whether the company will work directly in the KSeF panel or via an integrated system.
The most common KSeF access problems
Problems with the National e-Invoicing System (KSeF) in Poland often do not result from the system itself, but from poor access organisation within the company.
The most common situations include the following.
1. Missing or insufficient permissions
Logging in to KSeF does not automatically mean that a user can perform all necessary actions. In practice, the correct scope of permissions must be assigned separately, especially when the system is used by more than one person.
2. Incorrectly identified authorised person
This issue is especially common in companies. If the business does not properly identify the person who should obtain initial access to the system, or fails to complete the required formalities, the use of KSeF may be delayed.
3. Confusing the KSeF panel with system integration
Entrepreneurs often assume that if they intend to use accounting software, standard access to the KSeF panel will no longer be needed. In practice, user access, permissions and system integration settings should be treated as separate issues.
4. No defined document workflow
Even a correct login does not solve the problem if the company has not established who receives invoices, who verifies them and who passes them on to accounting. In practice, KSeF requires businesses in Poland to organise internal processes, not just activate access.
5. Leaving preparation to the last minute
This is particularly common in companies with a more complex structure. The later the business addresses access to the system, the greater the risk of operational delays and uncertainty over responsibilities.
How to prepare your company in Poland for working with the National e-Invoicing System (KSeF)
Preparing a company to work with KSeF should be treated as part of a broader effort to organise finance and accounting processes in Poland, rather than merely as a technical task of activating access. In practice, efficient use of KSeF requires not only a correct login, but also a clear division of responsibilities, properly assigned permissions and an agreed process for how invoices will circulate internally and reach the accounting team. This is especially important in businesses where documents are handled by different people, the entity operates as a company, or accounting support is partly outsourced.
From an organisational perspective, businesses should review in particular:
- who in the company should have access to KSeF and what scope of permissions they need,
- who is responsible for issuing, receiving and verifying invoices,
- whether the company will work directly in the KSeF Taxpayer Application or through an integrated system,
- how documents will be transferred to accounting and monitored on an ongoing basis,
- how to ensure continuity of invoice handling if key responsible persons are absent.
That is why a KSeF implementation should go hand in hand with better cooperation with an accounting office or a professional accounting partner. A well-structured model helps reduce the risk of errors, delays and misunderstandings in document circulation, while also making day-to-day tax and accounting compliance easier.
Our accounting team specialises in comprehensive accounting services in Poland. With many years of experience and a team of qualified specialists, we support businesses with accurate financial management and compliance with Polish regulations.
KSeF requires more from a business than simply logging in once. In practice, what matters is whether the company knows who should have access to invoices, how permissions should be assigned and how KSeF should be embedded into daily operations. The better these areas are prepared, the lower the risk of access problems, delays in document circulation and unnecessary organisational errors. That is why implementing KSeF in Poland should be treated not only as a new compliance obligation, but also as a good opportunity to improve cooperation with accounting and streamline the entire invoice handling process
