Mandatory E-Invoicing in Poland: Key Deadlines and What to Expect from KSeF 2.0

The Introduction of the National E-Invoicing System (KSeF)

On June 17, 2025, the Polish government approved a significant amendment to the VAT Act, marking a transformative shift in how businesses handle invoicing. This amendment, known as "KSeF 2.0," mandates the use of the National E-Invoicing System (Krajowy System e-Faktur, or KSeF) for issuing and receiving invoices. This centralized system aims to streamline the invoicing process and enhance the tax authorities' ability to monitor transactions and obtain detailed information on every business transaction.

The introduction of KSeF is not just a technological upgrade but a fundamental change in the business environment in Poland. It represents a move towards greater transparency and efficiency, aligning with global trends in digital transformation and e-governance. The new system will be mandatory for all businesses, with specific implementation timelines and transitional provisions to ease the transition.

Key Dates and Phased Implementation for Businesses

The implementation of KSeF is planned in two distinct phases to ensure a smooth transition for various business sizes:

• From February 1, 2026: Large enterprises, defined as those with over PLN 200 million in sales in 2024, will be required to adopt the KSeF for their invoicing needs.
• From April 1, 2026: All other businesses will need to transition to the KSeF, with certain exceptions and provisions for small businesses.

This phased approach allows larger enterprises, which typically have more resources and sophisticated IT infrastructure, to lead the way. Smaller businesses, which might face more challenges in adopting new technologies, are given additional time to comply, ensuring no business is left behind.  

The Transitional Period for Small Businesses

Recognizing the unique challenges faced by small businesses, the government has introduced a transitional period to provide additional support:

• Until the end of 2026: Small businesses whose monthly invoiced sales do not exceed PLN 10,000 will not be required to issue e-invoices. This provision aims to help the smallest or digitally excluded taxpayers document transactions more easily.

This transitional period is crucial for small businesses, which may lack the resources or technical expertise to immediately comply with the new requirements. By providing this grace period, the government aims to ensure that all businesses, regardless of size, can smoothly transition to the new system.

How KSeF Will Change Invoice Issuance and Reception

Under the new system, all invoices must be issued and received through the KSeF platform. This centralized approach not only simplifies the invoicing process but also provides tax authorities with real-time access to transaction data. Here's how the process will change:

• Centralized Invoicing: Businesses will no longer issue invoices through disparate systems. Instead, all invoices will be processed through the KSeF, ensuring consistency and standardization.
• Real-Time Monitoring: Tax authorities will gain immediate access to detailed information about each transaction, enabling better monitoring and compliance enforcement.
• Structured Data: Invoices will need to be structured according to predefined formats, making data processing and analysis more efficient.

The draft amendment also allows for offline invoicing, where invoices can be issued offline and uploaded to the KSeF platform the next day. This flexibility ensures that businesses can continue operations even in the absence of an internet connection.

Deferred Penalties and Learning Curve Considerations

To further ease the transition, the government has decided to defer penalties for KSeF-related errors until January 1, 2027. This decision acknowledges the learning curve associated with adopting a new system and gives businesses ample time to familiarize themselves with the KSeF platform without the immediate threat of penalties.

During this period:

• Invoice Issuance Flexibility: Taxpayers may still issue invoices from cash registers if the buyer provides a tax ID (NIP).
• Payment Processing: Taxpayers will not be required to include the KSeF number in payments for e-invoices, including the split payment mechanism (MPP).
• Error Leniency: No penalties will apply for errors in invoicing via KSeF, as the Ministry of Finance expects businesses to still be learning the system.

This deferred penalty period is a significant relief for businesses, providing a buffer to adapt to the new requirements without the risk of immediate financial repercussions.

Detailed Insights into the 'Offline24' Mode

One of the innovative features of KSeF is the "offline24" mode, which offers flexibility for businesses operating in environments with unreliable internet access:

• Offline Issuance: Businesses can issue structured invoices outside of the KSeF using a QR code.
• 24-Hour Window: These invoices must be uploaded to the KSeF platform within 24 hours, ensuring that all transactions are eventually recorded in the centralized system.

This feature ensures that businesses can maintain continuity of operations even when offline, while still complying with the new invoicing requirements. The use of QR codes facilitates easy tracking and verification of invoices once they are uploaded to the KSeF.

Impact on Buyers: Self-Identification and Compliance

The new system also introduces changes for buyers of goods and services. Specifically, buyers will need to self-identify when receiving structured invoices:

• VAT Number: Buyers registered for VAT must provide their VAT number.
• Tax ID (NIP): Buyers not registered for VAT, including exempt entities, must provide a tax ID (NIP) if the purchase is for business purposes and they possess such an ID.

This self-identification process ensures that all transactions are accurately recorded and attributed to the correct entities, enhancing the overall transparency and integrity of the system.

Preparing Your Business for a Seamless Transition to KSeF

As the mandatory implementation dates approach, businesses must take proactive steps to ensure a seamless transition to the KSeF platform:

• Evaluate Current Systems: Assess your current invoicing and accounting systems to determine what changes are needed to comply with KSeF requirements.
• Staff Training: Invest in training for your staff to familiarize them with the new system and processes.
• Engage with IT Experts: Work with IT professionals to integrate your existing systems with the KSeF platform and ensure that your data is structured correctly.
• Plan for the Transitional Period: If you are a small business, take advantage of the transitional period to gradually adapt to the new requirements without the pressure of immediate compliance.

By taking these steps, businesses can ensure they are well-prepared for the transition to mandatory e-invoicing, minimizing disruptions and maximizing the benefits of the new system.

In conclusion, the introduction of the National E-Invoicing System (KSeF) represents a significant shift in Poland's business landscape. By understanding the key aspects of this transition, businesses can navigate the changes effectively and leverage the benefits of a more transparent and efficient invoicing system. The phased implementation, transitional provisions, and deferred penalties all contribute to a smoother transition, ensuring that all businesses, regardless of size, can adapt to the new requirements and thrive in this evolving digital environment.