KSeF

From 1 February 2026, a new invoicing system will come into force in Poland – the National e-Invoicing System (Krajowy System e-Faktur – KSeF). This means that invoices will no longer be sent on paper or as PDF files, but electronically – directly to the central government system. Therefore, we kindly ask that the following information be included on invoices issued to the University of Warsaw (only national invoices – issued by Polish companies, foreign invoices will continue to be in paper or PDF form).

1. Customer details (as before)

University of Warsaw
Krakowskie Przedmieście 26/28
00-927 Warsaw
NIP: 5250011266

2. Additional information – very important (must be provided for all national invoices)

• IDWew number: 5250011266-11600
• Email address: faktura.d116@uw.edu.pl
• Name and surname of the person making the purchase (on the part of the University of Warsaw)

The above data should be included on the invoice in fields consistent with the logical structure of new invoices (XML file), in particular: „Podmiot3” (Entity3), „Stopka” (Footer), „Dodatkowy opis” (Additional description), „L2 – adres (Podmiot2)” (L2 – address (Entity2)), „Nazwa (Podmiot2)” (Name (Entity2)).

We hope that sellers will comply with this request. In case of problems on the seller’s side, please ask to include this information in the comments to the invoice.

3. When do the new rules come into force?

• 1 February 2026 – for large companies, including the University of Warsaw (turnover exceeding PLN 200 million),
• 1 April 2026 – for other companies (there are a few exceptions, which only apply to specific entities).

4. Why is this so important?

If this information is not included on the invoice, the University:

• will not be able to assign the invoice to the correct unit (in this case to our Faculty),
• and will ultimately not be able to pay it.

5. Other important information

• The seller is not required to provide a paper invoice or a PDF file.
• The invoice will be sent electronically to the KSeF system (XML format) and downloaded from there for payment.
• The seller may provide other confirmation of the transaction (e.g. confirmation of payment by card or bank transfer, a printout from the sales system or an e-mail confirmation), but this is not an invoice. The invoice will be issued and downloaded exclusively in the KSeF system.

Please inform the Research and Finance Section of your intention to make a purchase and then its realization at badania.historia@uw.edu.pl or finanse.historia@uw.edu.pl

Thank you for your cooperation and understanding!