KSeF Mandatory Dates in Poland 2026 — Who Must Use It and When?
The National e-Invoicing System (KSeF — Krajowy System e-Faktur) has moved from a distant prospect to an operational reality. In 2026 the phased rollout is well underway, and for most business owners the key question is now very specific: from which date must I issue invoices through KSeF if I run a sole proprietorship (JDG) or work as a B2B contractor?
The good news is that the schedule is publicly defined. The less welcome news is that many people are still reading outdated articles with old dates. Below is a practical breakdown of who is affected and when.
KSeF Rollout Timeline in 2026
The mandatory KSeF obligation is being introduced in stages.
From 1 February 2026
Companies whose sales in 2024 exceeded 200 million PLN gross must use KSeF.
From 1 April 2026
The obligation extends to all remaining businesses, including:
- sole proprietors (jednoosobowa działalność gospodarcza — JDG),
- B2B contractors,
- active VAT payers (vatowcy),
- VAT-exempt businesses,
- most other invoice-issuing entities not covered by the February wave.
From 1 January 2027
Full mandatory coverage will extend to the smallest entities currently benefiting from a transitional simplification for low-value invoices.
Does KSeF Apply to Sole Traders and Freelancers?
Yes. The legal form of your business is not the deciding factor. If you are legally required to issue invoices, you fall under KSeF according to the schedule above.
This means the following professionals are affected:
- software developers on B2B contracts,
- graphic designers and creative freelancers,
- consultants operating as sole traders,
- copywriters invoicing business clients,
- SEO specialists issuing invoices to companies.
For most small businesses and sole proprietors, the critical date was 1 April 2026.
What About Small Businesses and the 10,000 PLN Threshold?
The regulations include a transitional period running until the end of 2026. If the total VAT-inclusive sales documented by invoices issued outside KSeF in a given month does not exceed 10,000 PLN, a business can still issue paper or standard electronic invoices outside the system.
This is a temporary convenience, not a permanent exemption:
- it does not remove you from KSeF indefinitely,
- it applies only until 31 December 2026,
- from 2027, even the smallest businesses will be fully covered.
Do VAT-Exempt Businesses Also Fall Under KSeF?
Yes, in many cases they do. This is one of the most common misconceptions — many business owners assume that because they are not registered VAT payers, KSeF does not concern them.
In reality, the obligation is broader than just VAT-registered entities. It applies to taxpayers who are required to issue invoices, regardless of VAT status.
Is Receiving Invoices via KSeF Also Mandatory?
Yes. The obligation to receive invoices through KSeF is also part of the new document workflow. For many companies this means preparing:
- updated accounting procedures,
- integration with invoicing software,
- internal document circulation rules,
- access rights for accountants or accounting offices.
What Should You Do Now?
If you run a B2B business or sole proprietorship, do not leave preparations to the last minute. A sensible order of actions:
- Check how you currently issue invoices.
- Confirm whether your software supports KSeF 2.0.
- Define who should have access to your invoices in the system.
- Establish a procedure for technical failures.
- Test the document workflow with your accountant or accounting office.
Key Takeaway
For most Polish business owners the answer is straightforward: KSeF has been mandatory in practice since 1 April 2026, with the smallest businesses granted a temporary relief up to the 10,000 PLN monthly threshold.
If you work on B2B, issue invoices to clients and want to avoid chaos, get your procedures in place now. In the world of invoicing, "I'll deal with it later" tends to create very creative amounts of stress.
Tax rules in Poland change frequently. Always verify current requirements with a licensed accountant or at podatki.gov.pl.