Will KSeF Deadlines Be Postponed Again? What's Actually Left

The short answer: the big deadlines are behind us

The schedule is no longer a draft or a vague intention. It's written into the Act of 5 August 2025 (Journal of Laws 2025, item 1203), and the market already operates by it:

• 1 February 2026 — mandatory KSeF invoicing for taxpayers whose VAT-inclusive sales in 2024 exceeded PLN 200 million. The same day, mandatory receipt of invoices through KSeF began — for everyone, regardless of company size.

• 1 April 2026 — mandatory KSeF invoicing for all remaining taxpayers (VAT-active and VAT-exempt), including JDG (Poland's sole proprietorship) — the smallest join on 1 January 2027.

These dates are closed. There is no bill that would reverse the start of the obligation; the postponement the Ministry announced concerns only the penalties (see below). So the question "will they postpone it again?" — asked about the start of the obligation — is already moot. The start happened.

Why everyone expected another slip

It's worth understanding where that instinct comes from, because it's exactly what keeps people waiting.

KSeF was originally meant to be mandatory from 1 July 2024. In January 2024, the Ministry of Finance announced a postponement and a system audit — it had found defects too serious to ignore. KSeF 2.0 was built, with a new FA(3) invoice schema. The date moved to February 2026 (large firms), then April 2026 (everyone else) and January 2027 (the smallest) were added.

Every postponement reinforced the belief that "they'll just push it again." But the difference between 2024 and 2026 is fundamental. In 2024, the government was delaying a system that didn't work. In 2026, the system works, it's been tested, and it's broadly deployed. There's nothing left to fix with an audit — there's something to enforce.

What is genuinely still in play

Uncertainty hasn't vanished; it has moved to smaller, technical pieces. These are the ones worth tracking.

A transition window for the smallest firms (until 31 December 2026). Until 31 December 2026 taxpayers whose monthly gross value of B2B invoices subject to the KSeF obligation does not exceed PLN 10,000 may issue them outside KSeF. The cap does not count invoices to consumers, receipts with a NIP, simplified invoices up to PLN 450, or sales from a cash register. Exceeding the cap is irreversible: from the invoice that crossed it, you issue in KSeF. It's a temporary relief, not an exemption.

Penalties: from 1 January 2027 under the current act, with a postponement announced. Under the current act, penalties under Article 106ni of the VAT Act apply from 1 January 2027. On 16 September 2026 the Ministry of Finance announced it will move them to 1 January 2028; that is a bill not yet passed (in the government's register of legislative work since 23 September 2026), and it moves only the penalties, not the obligation to use KSeF. A penalty is up to 100% of the VAT amount on an invoice issued outside KSeF, or up to 18.7% of the total amount due where the invoice carries no VAT; it is payable within 14 days of the decision being served and is calculated on each invoice separately. From 1 January 2027 the KSeF obligation covers everyone, including the smallest. From that day there's also a duty to quote the KSeF number in payments between taxpayers, including the split-payment mechanism (MPP).

Tokens — a proposal, not yet a rule. Under the current rules KSeF tokens expire on 31 December 2026. At consultations on 9 June 2026 the Ministry of Finance proposed keeping them, but no regulation has been adopted yet, so moving to a KSeF certificate is the safer choice (KSeF consultations).

Notice the direction of these changes: the Ministry is proposing to soften rules and extend transitional relief, but it is not rolling back the core obligation. That matters, because many people are waiting for a "postponement" and instead getting something different — minor conveniences for those who are already inside the system.

The "no penalties in 2026" trap

The most common misreading is: "there are no fines until the end of 2026, so I have time." That's a trap.

First, the reprieve concerns administrative monetary penalties. The provisions of the Fiscal Penal Code apply from the moment the obligation takes effect — for instance, for fraudulent invoices documenting events that never happened. There is no separate transition period there.

Second, the duty to receive invoices through KSeF applies to everyone from 1 February 2026. If your counterparty issues an invoice in KSeF and you can't retrieve it, the problem is yours — penalties aside.

Third, 1 January 2027 is not a distant abstraction — from that day the obligation covers the smallest firms too. It's a matter of months. Companies that "wait for the penalties" will start implementing exactly when the buffer is gone — with no margin for integration issues, permissions, or testing.

How to prepare so no date surprises you

The trick isn't predicting when the Ministry will change something. It's separating the hard dates (already in force, won't move) from the soft ones (penalties, reliefs, technical detail — which can shift, usually toward leniency), then building foundations that survive either outcome.

1. Sort out authentication for the long run, not for now. Apply for a KSeF certificate. Under the current rules tokens expire on 31 December 2026; the Ministry proposed keeping them, but no regulation exists yet. The certificate is the destination. You cannot obtain one with a token — the first login requires a qualified signature, seal or Profil Zaufany. For offline invoices you need a KSeF certificate of the Offline type (QR code II).

2. Make sure you can receive FA(3) invoices. This is mandatory for everyone from 1 February 2026 — and the most commonly overlooked, because "I mostly issue invoices."

3. Have an outage procedure. Offline24 mode, codes, resubmission deadlines — not a curiosity, but a real scenario when KSeF is briefly unavailable.

4. Follow the source, not rumors. The schedule and announcements live at ksef.podatki.gov.pl. Base decisions on them, not on "I heard they're pushing it again."

5. Don't plan your rollout around a hoped-for delay. Treat any softening as a bonus, not as the basis of your plan.

Bottom line

KSeF's two most important dates — 1 February and 1 April 2026 — are behind us. What's left is a transition window through the end of 2026, penalties (from 1 January 2027 under the current act; a move to 2028 is announced but not yet law), and minor technical adjustments that lean toward leniency rather than reversal. The cheapest strategy is to be ready for the hard dates and treat reliefs as a bonus.

At Biurko we track the Ministry's changes for you — from the FA(3) schema to certificates and offline24 mode — so the next amendment is our problem, not yours. Set up your company in Biurko (14 days of the TEAM plan without a card, then the free FREE plan) at biurko.io.

FAQ

Will KSeF deadlines be postponed again? The main start dates — 1 February and 1 April 2026 — have already passed and won't be reversed. No bill would defer the start of the obligation; the postponement the Ministry announced concerns only the penalties (see below), not the obligation itself.

Are there penalties for KSeF in 2026? Administrative fines under Article 106ni do not apply in 2026. Under the current act they begin on 1 January 2027; on 16 September 2026 the Ministry of Finance announced it will move them to 1 January 2028 — a bill not yet passed, which moves only the penalties. Fiscal Penal Code provisions — for example, for fraudulent invoices — already apply. The absence of administrative penalties does not mean the absence of an obligation.

Will KSeF tokens disappear at the end of 2026? Under the current rules KSeF tokens expire on 31 December 2026. At consultations on 9 June 2026 the Ministry of Finance proposed keeping them, but no regulation has been adopted yet, so moving to a KSeF certificate is the safer choice.

When is KSeF mandatory for a sole proprietorship (JDG)? For sole proprietorships, mandatory KSeF invoicing applies from 1 April 2026. The smallest firms may issue outside KSeF until 31 December 2026 if the monthly gross value of their B2B invoices subject to the obligation does not exceed PLN 10,000, and from 1 January 2027 the obligation covers everyone.

What do I do if KSeF is unavailable? You can always use offline24 mode and issue an invoice outside the system; for QR code II you need a KSeF certificate of the Offline type. You send the document to KSeF by the next business day at the latest (after an unavailability announced by the Ministry, on the next business day after it ends). In an outage declared by the Ministry (emergency mode) you have 7 business days after it ends; after a total outage you do not send the invoices.