KSeF penalties: postponement to end-2027 announced, and what to tidy in your documents

Today the VAT Act provides that penalties for KSeF errors start on 1 January 2027. KSeF is Poland's National e-Invoicing System. On 16 September 2026 the Ministry of Finance announced that it would postpone the penalties to 31 December 2027. As of 5 October 2026 that is an announcement, not law in force. We checked the position on government websites, and below we write about what it means for your documents.

What the law says today

Under Article 106ni of the VAT Act the head of the tax office may impose a penalty of up to 100% of the tax shown on the invoice or, where the invoice shows no tax, up to 18.7% of the total amount due. The official portal ksef.podatki.gov.pl states that penalties will apply to breaches committed from 1 January 2027. The vendor of SaldeoSMART lists, among such breaches, an invoice issued outside KSeF despite the duty, an invoice not sent on time, and an invoice not sent to the system after an outage has ended. These are ceilings, not fixed rates. How the rules apply in a particular case is a question for a tax adviser, not for us.

An announcement is not yet a law

The Ministry of Finance notice of 16 September 2026 says: "Resort finansów wydłuża okres odroczenia kar za błędy związane ze stosowaniem Krajowego Systemu e-Faktur (KSeF) do 31 grudnia 2027 r." (the ministry extends the postponement of penalties for KSeF errors to 31 December 2027). The same ministry page adds that the change needs an act of parliament and that work on a draft is only starting.

The position on 5 October 2026: it is an announcement. There is no such act in the Journal of Laws and no parliamentary print on the matter in the Sejm. Press reports mention a draft published by the Government Legislation Centre. We could not confirm that on a government site, so we draw no conclusion from it. Whether the change will be passed before 1 January 2027 is not known today.

Postponing the penalties does not postpone the duty. From 1 January 2027 KSeF is mandatory for all businesses, and the ministry says the tax authorities are to react to invoices issued outside the system and to check whether that leads to VAT being settled unreliably.

Tidy document workflow pays off whatever the date

The date of the penalties may move, but from January you will be issuing and receiving invoices the new way in any case. So we look at this from the side of documents. It usually comes down to four things a company should have settled whatever the legislator decides:

• Who checks an invoice before it is sent. An invoice accepted by KSeF is not edited, a correction is issued, so checking before sending costs less than fixing afterwards.
• Numbering. The issuer assigns the invoice number and the system assigns the KSeF number. They are two different numbers and both must sit with the document.
• Outage and offline mode. A named person makes sure that an invoice issued in that mode reaches KSeF afterwards.
• Stand-ins. Who issues and sends the invoice when the person responsible is on leave.

At our clients we start by writing down who issues, who checks and who stands in, and we set up numbering and sending to KSeF during the SaldeoSMART (the document and accounting platform we implement) implementation, in one pass with sales invoices and the document workflow.

Sources: Ministry of Finance notice of 16.09.2026 (gov.pl), the ksef.podatki.gov.pl page of frequently asked questions, SaldeoSMART blog (in Polish): Kary KSeF od stycznia 2027 roku (5.08.2026, written before the announcement) and Zmiany w KSeF (lista aktualizowana). Legal position as of 5 October 2026. This describes documents, it is not tax advice.

The facts in this post come from an announcement by SaldeoSMART, the vendor. The assessment, examples and practical notes are ours.