Essential information before the mandatory KSeF

Essential information before the mandatory KSeF

From February 1, 2026, the National e-Invoice System (KSeF) will become the main tool for issuing invoices in Poland. However, it is worth knowing that there are exceptions where invoices can still be issued outside of KSeF:
  1. OSS (one-stop shop) procedure
  2. Sales to consumers (“voluntary,” FP (invoice to receipt))
  3. Special procedures: 
    1. section 7 - Non-EU procedure
    2. section 7a - Occasional international passenger transport
    3. section 9 - Distance selling of imported goods

Mandatory submission of invoices to KSeF

The National e-Invoice System is a topic that is currently generating a lot of information. However, it is worth remembering that some of this information may be incomplete or out of date, so every piece of news should be verified using reliable sources. This will help you avoid misinterpretations and be prepared for changes.
An entrepreneur is required to issue an invoice in KSeF even when
  1. the contractor is subjectively exempt from VAT (e.g. Article 113(1)(9) of the VAT Act)
  2. the subject of the sale is exempt from VAT (Article 43 of the VAT Act)
  3. a 0% rate applies to the subject of the sale (Article 83 of the VAT Act)
  4. the sale of goods or services is made to a foreign contractor (to the EU or to a third country)

Alert
Domestic sales to businesses must always be documented with an electronic invoice sent to KSeF.

Possibility of receiving paper invoices

We still have the possibility to receive invoices in their current manner, as a hard copy or PDF file.


Notes
There are cases in which receiving invoices in traditional (“paper”) form remains acceptable.
This applies to:

  1. purchase of services from contractors from third countries
  2. purchase of services from contractors from European Union countries
  3. purchase of goods from contractors from European Union countries (intra-Community acquisition),
  4. purchase of goods from contractors from third countries (imports)
  5. and from customers who cannot be legally obliged to use KSeF (e.g., small entrepreneurs until April 1, 2026, or entrepreneurs conducting business activity outside the territory of the Republic of Poland).

To accept - only invoices issued in KSeF

From February 1, 2026, businesses whose gross sales (i.e., including VAT) exceeded PLN 200 million in 2025 must issue and send all domestic sales invoices exclusively via KSeF

The same will apply to other businesses from April 1, 2026.

Info
This means that after February 1, 2026, purchase documents will be delivered electronically even to those businesses that are only required to issue their invoices in KSeF starting in April.

 

Deadlines and transition period

Please note that before the effective date, you can use KSeF voluntarily.
We have been using the National e-Invoice System in our office since November 2022, so we already have some experience and can support our clients in this area.

Idea
 We recommend that you gradually familiarize yourself with KSeF now so that the transition to the mandatory system is smooth and hassle-free for you.

With the new rules

As of the designated dates, i.e., February 1, 2026, or April 1, 2026, the following important rules will apply:

Alert
  1. No possibility to cancel an invoice. In the event of any mistake, the only form of correction will be to issue a corrective invoice.
  2. Obligation to send an invoice within 1 day
    1. In the event of a KSeF failure – within 7 days (“ failure mode”))
    2. In the event of a program/Internet connection failure at the entrepreneur's premises - 1 day after the failure has been rectified (“offline mode”)
    3. In “emergency mode” or “offline mode,” the issued invoice must contain 2 QR codes. The first is the “offline mode” code, and the second is the “issuer certificate” code. To issue invoices online, it will be necessary to have a KSeF certificate. KSeF certificates will be available from November 2025.
  3. For failure to send or late sending of an invoice
    1. an active VAT taxpayer will be penalized in the amount of VAT on the invoice;
    2. a VAT-exempt taxpayer will pay an amount corresponding to 18.71% of the invoice value.


 




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