This blog was last updated on November 5, 2025

KSeF, or the National E-Invoicing System, is Poland’s approach to continuous transaction controls (CTC), a trend that sees tax authorities gaining real-time visibility of transactions. The ‘clearance’ model implemented in Poland demands that invoices be issued in a structured electronic format and undergo validity checks, ensuring compliance and accuracy of e-invoices before they are sent to recipients.

Operational on a voluntary basis since 2022, the KSeF e-invoicing system is set to become mandatory in phases starting February 2026. Poland’s e-invoicing requirements encompass both VAT active and exempt entities, covering B2B and B2G transactions, while B2C e-invoicing remains optional. Importantly, the system includes both domestic and cross-border transactions, although with specific rules for invoice exchange in cross-border scenarios.

KSeF 2.0: key changes and features

KSeF 2.0 emerged as a direct response to stakeholder feedback during the voluntary implementation phase. After extensive public consultations, the Polish Ministry of Finance addressed several critical concerns raised by businesses. These included the need for offline invoicing capabilities during connectivity issues, support for B2C transactions, clearer rules for self-billing in cross-border scenarios, better handling of complex business structures like VAT groups, and many other concerns.

The resulting KSeF 2.0 framework includes both legislative changes (through the KSeF 2.0 Act and other implementing regulations) and technical enhancements (via the new FA3 schema and API). The new system adds support for optional B2C invoicing, previously unavailable in the voluntary phase, giving issuers the discretion to include such transactions within KSeF. It also introduces the KSeF certificates, which will be used for authentication in the system and for the generation of the QR code used in the offline modes. Special attention is given to offline modes, particularly the “offline 24” mode, which allows for invoice submission by the next business day in case of issues on the taxpayer’s side.

Key functionalities and adjustments included in KSEF 2.0

• B2C e-invoicing: Businesses can optionally issue B2C e-invoices via KSeF, with no consumer consent required, although consumers must request an invoice. If the issuer chooses to issue via KSeF, consumers retain the right to request receiving an alternative invoice format outside of KSeF.
• Offline modes: Four distinct offline scenarios are supported:
  • “Offline24” for connectivity issues on the taxpayer side
  • Standard “Offline Mode” for planned system maintenance
  • “Failure Mode” for unexpected system errors on the tax authority’s side
  • “Total Failure Mode” for extraordinary situations threatening country infrastructure
• QR codes: Two types of QR codes are introduced to ensure invoice authenticity and access, crucial for invoices exchanged outside KSeF:
  • Access QR code provides verification in KSeF
  • Certificate QR code ensures invoice integrity and authenticity

QR codes will be required when exchanging invoices outside of KSeF both in online or offline modes with the need to add a second QR code for invoices issued in offline mode and sent to the recipient before KSeF clearance.

• Postponements: Until 31 December 2026, several requirements are postponed, including financial penalties for KSeF-related errors and violations, the obligation to include KSeF numbers in payments, and the ability to continue issuing cash register invoices outside KSeF.
• FA3 schema enhancements: The new logical structure introduces expanded fields for VAT groups, government units, employee expenses, and a new optional attachment element, which allows for structured XML attachments for complex invoices with detailed item data, subject to prior registration with the tax authority.

The timeline to KSeF implementation

• The timeline for KSeF implementation is marked by key milestones set by the Polish Ministry of Finance:
• June 2025: the FA3 schema and API documentation were published, marking a significant step towards KSeF 2.0’s rollout.
• September 2025: testing of the new system will commence, with the ability to download internal certificates starting in November of this same year.
• February 2026: the mandatory shift to KSeF 2.0 will begin for large taxpayers, defined as those with sales exceeding 200 million PLN (approx. €46 million) in 2024
• April 2026: KSEF becomes mandatory to all other taxpayers.
• Importantly, businesses with monthly sales up to 10,000 PLN ( €2,300) will be granted a transitional exemption until January 2027.

What’s next for Poland e-invoicing requirments?

As Poland advances towards the full implementation of KSeF 2.0, businesses must stay informed and prepared for these regulatory changes. The system’s phased rollout offers a window for adaptation, but early compliance will ensure smoother transitions and mitigate potential disruptions.

Sovos has created a number of resources to help businesses prepare for Poland’s KSEF 2.0 e-invoicing requirements:

• KSEF 2.0 FAQ document – a detailed resource addressing common queries to help support your journey with KSEF 2.0
• Poland e-invoicing tax rules – the main webpage to stay up to date with current and upcoming e-invoicing regulations in Poland
• KSEF timeline – a comprehensive timeline of Poland’s e-invoicing mandate, updated with the latest announcements from the tax authority