Accounting and national e-invoicing system (KSeF) will be one of the most significant organizational and tax challenges that businesses will face in the coming years. The National e‑Invoicing System (KSeF) is not just a technical tool for issuing invoices in a new format, but a solution that fundamentally affects how accounting is managed, how documents circulate, and the scope of responsibility for both entrepreneurs and the entities handling their settlements.
Table of Contents
- What Is the E-Invoicing System (KSeF) in Poland, and Why Does It Change Accounting?
- Who Is Required to Use the E-invoicing System (KSeF) and When? Implementation Timeline
- Implementing e-invoicing system (KSeF) – Where to Start in Your Company?
- Obtaining Access, Granting Authorisations, and Managing Roles
- How Does KSeF e-Invoicing Change Document Circulation and the Work of Accounting?
- Responsibility for Implementation and Errors – Who Is Responsible for What?
- Challenges and Risks in Implementing the KSeF e-Invoicing System
- Invoicing Changes in 2026 – Key Consequences for Accounting
- Practical Tips for Smooth Implementation of the National e-Invoicing System KSeF
- Accounting and National E-Invoicing System (KSeF) – Summary
- FAQ – Accounting and National e-Invoicing System (KSeF)
What Is the E-Invoicing System (KSeF) in Poland, and Why Does It Change Accounting?
The National e-Invoicing System (KSeF) is a government teleinformatics platform. It enables issuing, receipt, and archiving of structured invoices. Each invoice exists in the system as an XML file. It is compliant with the logical structure defined by the Ministry of Finance.
From the accounting point of view, it is crucial that:
- each invoice receives a unique identification number,
- data from invoices is automatically transferred to the tax administration,
- the invoice issue date is the moment it is accepted into the e-Invoicing System (KSeF),
- the invoice is considered to have been delivered to the buyer as soon as it is available in the system.
The e-invoicing system (KSeF) has been operating in Poland since 2022 voluntarily. From 2026, it will become mandatory. Its purpose is the full digitalisation of document circulation. Another objective is the simplification of tax settlements. Tightening of the VAT system and reduction of errors and abuses in invoicing are also the goals.
Who Is Required to Use the E-invoicing System (KSeF) and When? Implementation Timeline
The obligation to use the National e-Invoice System has been divided into stages. This results from communications of the Ministry of Finance. Information published on government websites also indicate that. The schedule covers both issuing and receiving invoices via the e-invoicing system (KSeF)
According to current information:
- from 1 February 2026, the obligation to issue invoices in the e-invoicing KSeF system will apply to the largest taxpayers. This means the ones whose turnover for 2024 exceeded 200 million PLN
- from 1 April 2026, the obligation to issue invoices in the system will apply to other VAT taxpayers. This includes sole proprietorships and companies,
- from 1 January 2027, the obligation will be extended to micro-entrepreneurs. This means those whose monthly turnover does not exceed 10 thousand PLN gross.
From 1 February 2026, all companies must receive invoices this way. Regardless of their size. Every business will have to receive invoices via the KSeF e-invoicing system. This will apply even if invoices are not yet issued through the system itself.
| KSeF e-invoicing system implementation stage | Subjective scope | Effective Date |
| Stage I | Taxpayers with turnover > PLN 200 million (2024) | from 1 February 2026 |
| Stage II | Other VAT taxpayers (including sole proprietors and companies) | from 1 April 2026 |
| Stage III | Micro-entrepreneurs (turnover up to 10 thousand PLN per month) | from 1 January 2027 |
| Obligation to receive invoices | All companies | from 1 February 2026 |
Implementing e-invoicing system (KSeF) – Where to Start in Your Company?
Analysis of current accounting processes and document workflow
The first step in the implementation of the KSeF e-invoicing system is simple. You conduct a detailed analysis of current state. Verify document circulation in the company. It is worth determining:
- in what form invoices are currently received (paper, PDF, e-mail),
- who is responsible for their verification, acceptance and accounting,
- at what stage delays or risk of errors occur.
Such process mapping helps identify areas requiring changes after the transition. Especially when it comes to document workflow and the KSeF e-invoicing system.
Selection and Integration of Software Compatible with the KSeF e-Invoicing System
The next stage is to verify whether the accounting or ERP system currently in use supports KSeF. Check whether it will require an update or integration with an external tool.
Entrepreneurs can use:
- free tools made available by the Ministry of Finance,
- commercial accounting systems and platforms integrated with the KSeF e-Invoicing system,
- other solutions that enable the integration of the KSeF system with the existing ERP.
Choosing the right solution is crucial for the security of accounting processes.
Obtaining Access, Granting Authorisations, and Managing Roles
Operating KSeF e-invoicing requires authentication in the system and granting appropriate user permissions. This may include, among others, the use of a qualified electronic signature or tokens.
From the perspective of KSeF authorisations, it is particularly important to define:
- who has the right to issue invoices,
- who has the right to receive and download them from the system,
- who is responsible for accounting?
This has a direct impact on the scope of liability in the event of errors. Especially when cooperating with an accounting office.
How Does KSeF e-Invoicing Change Document Circulation and the Work of Accounting?
In the KSeF model, sales and purchase invoices function within a central system. The seller submits the document to KSeF, and the buyer retrieves it from the system. This means that the traditional exchange of invoices between business partners changes.
In practice:
- invoice visualisations (e.g. PDFs generated from XML files) may be used in accounting processes,
- it is crucial to confirm that the invoice has been registered well in KSeF,
- despite automation, invoices still need posting, description, and substantive approval.
For accounting offices, this means a shift from periodic to ongoing data handling. This requires workflow adjustments and increases the importance of internal controls.
Responsibility for Implementation and Errors – Who Is Responsible for What?
| Area | Responsible entity | Example of responsibilities |
| Implementation of the KSeF e-invoicing system in the company | Entrepreneur | Providing access to the system, tool selection, and process organisation |
| Issuing invoices in the KSeF e-invoicing system | Authorized person | Data accuracy, VAT rates, compliance |
| Invoice posting | Accountant/accounting office | Correct posting and recording in registers |
| Supervision and formal responsibility | Entrepreneur | Tax and administrative responsibility |
Formal responsibility for correctly using the KSeF e-invoicing system rests with the entrepreneurs. They are also responsible for the accuracy of all invoices as VAT taxpayers.
At the same time, if employees, accountants, or accounting offices are authorised to handle KSeF:
- they may bear responsibility for substantive errors (e.g. VAT rates, contractor data),
- the scope of this responsibility should be clearly defined in the contract.
Therefore, it is crucial to clearly define cooperation with an accounting office. This is especially important when it comes to e-invoicing KSeF 2026 obligations.
Challenges and Risks in Implementing the KSeF e-Invoicing System
The implementation of the e-invoicing system is associated with a number of potential risks. They include:
- technical problems resulting from the lack of full integration of systems,
- errors made by untrained personnel,
- unclear division of roles and responsibilities in the company,
- risk of tax penalties for incorrectly issued or posted invoices.
Therefore, changes in invoicing in 2026 should be treated as an organisational project. It is more than just a system update.
Invoicing Changes in 2026 – Key Consequences for Accounting
The widespread KSeF implementation in 2026 will change invoicing rules. It affects every step: issuing, circulation, booking, and archiving of invoices. Adapting to this centralised model is crucial for entrepreneurs and accounting offices.
Practical Tips for Smooth Implementation of the National
e-Invoicing System KSeF
To ensure smooth implementation of the National e-Invoicing System (KSeF), it is advisable to:
- start preparations in advance and test new procedures,
- appoint a project team including accounting, IT, and decision-makers
- update or implement compliant software,
- establish clear procedures for the circulation and acceptance of documents,
- train employees responsible for invoicing and accounting.
Accounting and National E-Invoicing System (KSeF) – Summary
The accounting and national e-invoicing system KSeF is not only a new invoice format. It is a change to the entire invoicing and document circulation model within a company. Implementing KSeF requires both technical and organisational preparation. Formal responsibility lies primarily with the entrepreneur. With proper planning, the system can bring real benefits. Especially in the form of automation and greater control over accounting processes.
Use Professional Support for Implementation of the National e-Invoicing System KSeF
Implementing the National e-Invoicing System KSeF is a process that combines tax, accounting, technical, and organisational issues. To reduce the risk of errors and ensure compliance with regulations, it is worth using professional support.
Our specialists can assist, among others, with:
- assessing the company’s readiness for KSeF implementation,
- selecting and integrating an accounting system with KSeF,
- developing document circulation procedures,
- defining the scope of authorisations and responsibilities,
- ongoing handling of structured invoices.
Professional support ensures KSeF is implemented safely and efficiently. It is tailored to your company’s operations. Contact us today!
FAQ – Accounting and National e-Invoicing System (KSeF)
Will the National e-Invoicing System (KSeF) completely replace paper and PDF invoices?
Once the mandatory KSeF enters into force,invoices will be issued in structured (XML) form. They will be transmitted via the system. Paper and PDF documents will no longer be the primary form of invoicing. Still, there might be some statutory exceptions.
Does the entrepreneur have to operate the National e-Invoicing System (KSeF) personally?
No. KSeF handling may be delegated to an employee, an accountant, or the accounting office. Appropriate authorisations must be granted first in the system. Formal responsibility remains with the entrepreneur.
Is an invoice visualisation from the KSeF system (e.g. PDF) sufficient for accounting purposes?
Yes. Invoice visualisations may be used in accounting processes. Yet, the invoice must be correctly registered in KSeF first. It must have an assigned identification number.
What are the most common mistakes when implementing the National e-Invoicing System (KSeF)?
The most frequent problems include a lack of system integration. Incorrect assignment of authorisations, absence of internal procedures, might also be problematic. Insufficient staff training is also a common mistake.
Is an accounting office liable for errors in the National e-Invoicing System (KSeF)?
An accounting office may be liable for errors within the scope of tasks entrusted to it. Yet, the scope of authorisation is crucial. The scope of liability should be precisely defined in the contract.
Will the National e-Invoicing System (KSeF) change the way tax audits are conducted?
Yes. KSeF provides tax authorities with ongoing access to invoice data. In practice, this may result in faster and more automated tax audits.