The mandatory National e-Invoice System (KSeF 2.0) will be launched in 2026.

KSeF is an ICT platform used, among other things, to issue, send, receive, and store structured invoices (i.e., electronic invoices whose content is organized according to a template provided by the tax authorities).

The e-invoicing obligation will be introduced gradually:

From February 1, 2026 – for the largest entities, i.e., entrepreneurs whose gross sales in 2024 exceeded PLN 200 million.

From April 1, 2026 – for other entrepreneurs, except for the smallest taxpayers.

From January 1, 2027 – for the smallest entities whose sales documented by invoices will not exceed PLN 10,000 gross per month in 2026.

It is worth remembering that readiness to receive purchase invoices in KSeF will in practice be required from February 1, 2026, even if the obligation to issue structured invoices arises later for a given taxpayer.

Facilities for taxpayers using KSeF are also provided for, such as:

The possibility of adding structured attachments to e-invoices (provided that they do not contain marketing or commercial content).

The “offline24” mode, which allows structured invoices to be sent to the system on the next business day.

Free tools for e-invoicing and communication with KSeF (KSeF Taxpayer Application, e-mikrofirma) – in practice, these will only work for micro and small businesses.

Importantly, no penalties will be imposed for non-compliance with KSeF throughout 2026. This period is intended to allow for a smooth transition to the new regulations.

The implementation of KSeF in medium and large organizations is almost always complicated and time-consuming. It usually requires the cooperation of the entire organization – the challenges associated with e-invoicing go beyond the financial, accounting, and IT spheres. Our experts are available to assist you throughout the process of transforming and adapting your company to the new invoicing standard.

Check out our materials on KSeF:

KSeF

KSeF – offer