Invoice outside KSeF
If you issue an invoice outside KSeF despite the obligation, the head of the tax office imposes, by decision, a financial penalty of up to 100% of the VAT amount shown on that invoice.
up to 100% VATFrom January 1, 2027, every invoice issued outside KSeF carries the risk of a financial penalty of up to 100% of its VAT amount (art. 106ni ustawy o VAT). Check your maximum exposure — before the tax office does.
Total monthly sales value including VAT (gross).
Estimated share of sales invoiced outside KSeF.
10,000 zł invoiced outside KSeF · incl. 1,870 zł VAT · penalty cap: 100% of VAT
Legal basis: art. 106ni ustawy o VAT. The law sets an upper limit (“up to”) — the actual amount is calibrated in the proceedings.
This calculator is for illustrative and educational purposes only. The result shows the statutory upper limit of the penalty (“up to”), not a prediction of its actual amount — penalties are imposed by the head of the tax office by way of a decision, taking into account the circumstances of each case. The information on this page does not constitute tax or legal advice.
KSeF becomes mandatory for the largest taxpayers — 2024 sales (incl. VAT) above 200 million zł.
In forceKSeF becomes mandatory for all other active VAT payers.
In forceEnd of the transition period: financial penalties up to 100% of VAT and the full obligation for everyone — it also covers cash-register invoices and micro sellers (up to 10,000 zł per month).
Sanctions startIf you issue an invoice outside KSeF despite the obligation, the head of the tax office imposes, by decision, a financial penalty of up to 100% of the VAT amount shown on that invoice.
up to 100% VATIf you issue an invoice in offline24 or emergency mode but fail to send it to KSeF within the statutory deadline — the same penalty applies, up to 100% of the VAT amount.
up to 100% VATFor invoices without a VAT amount (e.g. exempt sales), the penalty may reach up to 18.7% of the total amount due shown on the invoice.
up to 18.7%Biurko issues invoices straight to KSeF and keeps track of offline modes and deadlines — start for free.
Financial penalties apply from January 1, 2027. The KSeF obligation itself starts earlier — February 1, 2026 (largest taxpayers) and April 1, 2026 (everyone else) — but during the transition period no penalties are imposed (the so-called soft landing).
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