KSeF in Poland 2026: Mandatory E-Invoicing for B2B Freelancers
Short answer: Since 2026 most Polish businesses must issue B2B invoices through the state's KSeF platform; invoices to consumers and foreign firms without a Polish establishment are exempt, and sellers invoicing up to 10,000 zł a month may stay on paper or ordinary e-invoices only until 31 December 2026.
If you run a business in Poland - a sole proprietorship (JDG), a company, freelance B2B work - the way you invoice changed fundamentally in 2026. Paper and PDF invoices are being replaced by *faktury ustrukturyzowane*: structured invoices issued through KSeF, the state's National e-Invoicing System. Here is what the rules mean for expats with a Polish business, as of October 2026, based on the VAT Act (consolidated text, *Dziennik Ustaw* 2026 item 1263) and the Ministry of Finance's KSeF pages.
What KSeF is
KSeF (Krajowy System e-Faktur) is the Ministry of Finance's central platform for issuing, sending, receiving and storing invoices. Since 1 February 2026, Article 106ga(1) of the VAT Act obliges taxpayers to issue structured invoices through it. A structured invoice exists only inside the system: it is created in the official XML schema, sent to KSeF, and receives a KSeF identification number. Under Article 106na, it is treated as issued on the day it reaches KSeF.
That shift matters in practice: the system copy is the legal original. What you email a client is a visualisation of the KSeF record, not the invoice itself.
Who must use it - and who is exempt
The obligation covers taxpayers with a business seat or a fixed establishment in Poland. Article 106ga(2) carves out the main exemptions:
- businesses with no seat and no fixed establishment in Poland (or whose Polish establishment does not participate in the supply),
- supplies settled under the special OSS procedures,
- invoices to private consumers - individuals not running a business. B2C invoicing stays outside mandatory KSeF,
- flat-rate farmers using the Article 113a exemption.
For a foreign freelancer with a Polish JDG, the bottom line is simple: if your clients are businesses, KSeF applies to you. Selling services to private individuals does not require KSeF invoices.
The 2026 phase-in and the easements still running
The obligation arrived in two waves, and two transitional easements are still in force until the end of 2026:
- From 1 February 2026 - businesses whose 2024 sales including tax exceeded 200 million zł had to issue through KSeF (the rest could wait, per the transitional Article 145l).
- From 1 April 2026 - the obligation extended to essentially all businesses.
- Until 31 December 2026 - taxpayers whose total invoiced sales in a month do not exceed 10,000 zł may still issue ordinary electronic or paper invoices (Article 145m). Cross the 10,000 zł line and KSeF applies from the invoice that breaches it.
- Until 31 December 2026 - cash-register invoices and receipts meeting the conditions to count as invoices may still be issued outside KSeF (Article 145n).
From 1 January 2027 the easements expire and KSeF becomes the universal B2B standard.
How to issue a KSeF invoice
You do not need paid software. The Ministry of Finance provides free official tools, described on its KSeF pages at podatki.gov.pl:
- Aplikacja Podatnika KSeF 2.0 - the government's free web application for issuing and downloading invoices, aimed at smaller businesses,
- the KSeF 2.0 mobile app,
- commercial accounting and invoicing software connected to the KSeF API - the natural choice once volumes grow.
The ministry also runs a KSeF helpline (22 330 03 30) and publishes step-by-step onboarding guides for sole traders and SMEs.
QR codes, offline mode and outages
Every structured invoice can carry a QR code that lets anyone verify it in KSeF. The Act also plans for connectivity problems. Under Article 106nda, you may issue an invoice offline in the schema format - but you must then send it to KSeF no later than the next working day, and the invoice needs the offline QR markings, which requires a KSeF certificate confirming the issuer's identity. Separate procedures apply during officially announced KSeF breakdowns (Articles 106ne-106nh).
What buyers should know
Business buyers receive invoices through KSeF itself - the system is where you collect your purchase invoices, so keep your access credentials current even if you only buy. Consumers and foreign buyers without a Polish establishment receive the invoice in a form agreed with them, marked with the verification QR code.
Frequently asked questions
### Do I have to use KSeF for B2C sales to private customers?
No. Invoices to individuals who do not run a business are exempt from the KSeF obligation under Article 106ga(2)(4) of the VAT Act. KSeF covers B2B invoicing.
I invoice under 10,000 zł a month - do I need KSeF yet?
Not until the end of 2026. The transitional Article 145m lets taxpayers with monthly invoiced sales of up to 10,000 zł keep issuing ordinary electronic or paper invoices until 31 December 2026. From 1 January 2027 the easement ends.
Does a foreign company without a Polish establishment need KSeF?
No - the obligation applies to taxpayers with a business seat or a participating fixed establishment in Poland. Such foreign businesses may use KSeF voluntarily.
Do I have to pay for invoicing software?
No. The Ministry of Finance provides the free Aplikacja Podatnika KSeF 2.0 web app and a mobile app; commercial software with a KSeF integration is optional.
