Complying with KSeF in Poland

Progression and implementation approach

We have covered the background and challenges behind the EU-wide change to e-invoicing in a previous article. Read also about our learnings from Italy, the pioneer of e-invoicing among EU member states. 

Like Italy, Poland has taken a centralized approach in routing invoices through its national e-invoicing platform, the Krajowy System e-Faktur (KSeF), developed by the Polish Ministry of Finance. The platform is key to Poland’s transformation effort, since all issued invoices must be reported to this system to ensure compliance with the new regulations. 

Each invoice submitted in the national e-invoicing system has a specific number, containing the seller's taxpayer’s identification number (NIP), the invoice issue date in YYYYMMDD format, two automatically generated values consisting of six characters each, and the automatically calculated value. A QR code must be provided in every invoice to enable visualization in a different format. The structured and uniform format allows for the standardization of e-invoices, which will result in faster and more efficient payment processing due to the reduced need for manual intervention. Some of the key changes the new system will introduce include eliminating the need to issue a duplicate copy of an invoice, shortening the VAT refund deadline from 60 to 40 days, and removing the necessity for businesses to archive e-invoices, as they will be stored in KSeF for 10 years.

Since a stable and smooth technical solution is prioritized, free tools and trainings are offered, and businesses are encouraged to test the platform extensively in order to address issues before full implementation. A mobile application is also in development, providing users with access to basic features, such as viewing, issuing and correcting invoices directly from their smartphones.

Who is affected by e-invoicing?

Although initially scheduled for an earlier start, the implementation date of e-invoicing in Poland had to be postponed due to issues identified within KSeF. Now, the e-invoicing requirements will first apply to businesses with an annual sales value exceeding 200 million Polish zloty – approximately 46 million euros – starting in February 2026. By April 2026, it will be mandatory for all entrepreneurs operating in Poland that generate invoices for goods and services supplied within Poland. This mandate applies to business-to-business transactions (B2B), while business-to-consumer transactions (B2C) are not affected yet. 

As of now, foreign entities registered as VAT taxpayers but without a registered office or a fixed establishment in Poland are exempt from the new regulations. The same applies to those, who only have a fixed establishment in Poland (but without a registered office), that isn’t directly involved in the transactions for which the invoice is issued. However, further clarifications concerning the definition of a “fixed establishment” of foreign entities are expected and currently need to be assessed based on the company’s specific situation. Additionally, taxpayers have the option to offset the cost of implementing KSeF in their income tax, and active VAT payers may deduct input tax on purchases related to the KSeF implementation. 

Grant Thornton Poland’s solutions to master technological challenges

The transition to KSeF presents businesses with multiple challenges, such as ensuring all required information is integrated into accounting systems, distinguishing between B2B and B2C invoices, and determining KSeF obligations for foreign entities. These complexities require optimizing internal processes and IT systems that need to remain compatible with KSeF. If done right, cost benefits can be achieved by making accounting processes more efficient through automation.

As a result, the Outsourcing Department of Grant Thornton Poland is working on their own tools adjusted for future KSeF obligations. “Our Excellence Center team is overseeing the optimization of these IT tools to ensure that they are always up-to-date and function efficiently for both facultative and obligatory use. We will support clients with issuing sales e-invoices as well as receiving and posting purchase e-invoices in our accounting system.” said Anna Łuńska, Partner at Grant Thornton Poland. 

Businesses can rely on trainings, consultations, and tailored analyses, which focus on identifying opportunities for automation and defining project goals and risks at a pre-implementation stage. Assistance in the mapping process, verifying selected transactions or activities included in structured invoices, analyzing regulations and contracts, as well as maintaining communication with tax authorities are examples of services that can help businesses navigate the challenges. These services are integrated in a five-step implementation plan devised by Grant Thornton Poland to ensure a structured approach for the implementation of KSeF:

1. Identify: Defining project goals, preparing a schedule, and identifying risks.
2. Analyze: Analyzing of sales and purchase invoice processes, ensuring compatibility with KSeF, consulting with contractors to include additional information in structured e-invoices and identifying opportunities for process optimization and automation
3. Adapt: Modifying the IT systems and integrating them with KSeF
4. Test: Conducting tests, including with contractors
5. Document: Adapting procedures, regulations, and contract templates.

As e-invoicing processes evolve throughout the European Union to conform with new directives, our clients can be confident that their entities remain fully compliant with local regulations and receive the highest level of support from Grant Thornton’s trusted network of professionals.

The article was written by Lars Korte and Anna Łuńska.