KSeF will become mandatory for most entrepreneurs in 2026. We explain who exactly will be covered, what the implementation stages are and how to prepare your company without stress.
The National e-Invoice System (KSeF) is the central platform of the Ministry of Finance, where entrepreneurs will issue and receive structured invoices. After years of postponements, KSeF will become mandatory in 2026 — first for larger entities, then for the rest. Here's what you should know today.
As a rule — all active VAT taxpayers registered in Poland. The obligation is introduced in stages depending on sales value: • Large taxpayers (sales above PLN 200 million annually) — obligation earlier. • Other active VAT taxpayers — in the second stage. • VAT-exempt taxpayers — in the third stage. Exact dates and thresholds may be adjusted by regulation — we monitor them on an ongoing basis and inform our clients.
An invoice issued in KSeF receives a unique KSeF number and is automatically delivered to the buyer. You don't need to send it by email or print it. A paper or PDF invoice loses its validity — it will not be treated as an invoice within the meaning of the VAT Act (with exceptions for system failures and consumers). The KSeF number replaces the invoice number. Payment for an invoice marked MPP (split payment) must contain this number.
1. Check whether your accounting/invoicing software is integrated with KSeF. wFirma — which we work with — supports KSeF natively. 2. Designate persons authorized to issue invoices in KSeF (owner, accountant, employees). 3. Train the team — especially sales and customer service. 4. Update contract templates and procedures (e.g. payment terms run from the date of invoice delivery in KSeF).
The act provides for an emergency mode — in case of KSeF unavailability or failure on the taxpayer's side, invoices can be issued offline (with appropriate marking) and entered into KSeF within a specified period after system operation is restored.
You don't have to face KSeF alone. We will help implement it in your company — from wFirma configuration, through granting permissions, to training the team. Contact us to schedule a free consultation.