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KSeF (Krajowy System e-Faktur) is the Polish government system where invoices are issued, received and stored as structured XML files. Since 1 February 2026 every business receives invoices from Polish suppliers through it. Issuing in KSeF became mandatory on 1 February 2026 for companies whose 2024 sales were above PLN 200 million, and on 1 April 2026 for everyone else, sole traders and VAT-exempt sellers included. Until 31 December 2026 you may still issue invoices outside KSeF in any month in which those invoices total no more than PLN 10,000 including VAT; from 1 January 2027 that relief ends.
The dates, in order
- Since 1 February 2026: every business receives invoices through KSeF, and companies with 2024 sales above PLN 200 million issue them there.
- Since 1 April 2026: all other businesses issue invoices in KSeF, whatever their legal form, VAT-registered or VAT-exempt.
- Until 31 December 2026: invoices may still be issued outside KSeF (paper or PDF) in a month in which they total no more than PLN 10,000 including VAT.
- From 1 January 2027: KSeF is mandatory for those smallest sellers too.
The PLN 10,000 relief, exactly
Only invoices that would otherwise have to go through KSeF count toward the limit. Invoices to private individuals (consumer invoices) and invoices from a cash register do not count. If an invoice takes the month over PLN 10,000, that invoice and every later one must be issued in KSeF. The relief covers issuing only: you must still receive your suppliers' invoices in KSeF.
Who is outside it
- Invoices to private individuals who do not run a business do not have to go through KSeF; you may still issue them there if you want.
- Invoices you receive from foreign suppliers are not reported to KSeF.
- Invoices to clients abroad are issued in KSeF like any Polish invoice, then given to the client in an agreed way (for example a PDF carrying the KSeF QR code).
What to do now
- Log in to KSeF once (with Podpis Zaufany, a qualified signature or, according to the ministry, mObywatel) and check the invoices addressed to your NIP: KSeF sends no notifications.
- Pick how you will issue: the ministry's free Aplikacja Podatnika KSeF (web), the free KSeF mobile app, e-mikrofirma in e-Urząd Skarbowy, or accounting software connected to KSeF. No paid program is required.
- If you use the PLN 10,000 relief, add up your business invoices each month, and switch before 1 January 2027 at the latest.
- If an accounting office issues your invoices, give it KSeF permissions instead of sharing your login.
Received an e-invoice from a supplier? Open the XML or Factur-X PDF as a readable invoice in the free viewer. Viewer only: it shows the data and does not validate, certify or receive invoices.
Questions
I am VAT-exempt. Does KSeF apply to me?
Yes. According to the Ministry of Finance, every taxpayer who must issue an invoice, VAT-registered or exempt, issues it in KSeF from 1 April 2026, subject to the PLN 10,000 relief until the end of 2026.
Does my client have to accept a KSeF invoice?
No. An invoice counts as received when KSeF gives it its number. Only for consumers and clients abroad do you agree how to pass it on, for example as a PDF.
What if KSeF or my internet is down?
KSeF has offline modes: you issue the invoice outside the system and send it to KSeF later, by the next working day in the usual case and within 7 working days after an announced outage. Offline invoices given to the buyer carry QR codes.
Related guide: e-invoicing in Germany · E-invoicing in France · E-invoicing in Belgium (Peppol) · VAT calculator · All guides