There are 105 days left until 1 January 2027 — counting from 18 September 2026. Fifteen weeks, three month-end closes.
On 16 September, Poland's Ministry of Finance announced it would extend the deferral of penalties for KSeF errors until 31 December 2027. Within hours, the headline circulating in business groups was "KSeF postponed by a year." It isn't. The ministry deferred penalties. It did not touch the transition exemptions written into the VAT Act — and those expire on 31 December 2026.
If you run a Polish subsidiary, a branch, or a Polish entity inside a group finance function, the distinction matters. Penalties affect your risk exposure. The exemptions affect your invoicing and treasury processes, which take longer than 105 days to change.
KSeF (Krajowy System e-Faktur) is Poland's national e-invoicing platform. Since 1 February 2026 every VAT taxpayer must be able to receive structured invoices through it; issuing became mandatory for large taxpayers on 1 February 2026 and for everyone else on 1 April 2026.
Three exemptions that expire on 31 December 2026
These are transitional provisions of the Polish VAT Act. The September announcement does not cover them.
What expires Legal basis Who it affects Exemption for the smallest taxpayers: invoiced sales up to PLN 10,000 gross per month Art. 145m, VAT Act micro-entities still invoicing outside KSeF Invoices issued from cash registers Art. 145n(1)(1) retail, hospitality, any operation with an online cash register Receipt with buyer's NIP up to PLN 450 treated as a standalone simplified invoice Art. 145n(1)(2) anyone selling small amounts to businesses
And one obligation that does not expire but begins: the KSeF number in bank transfer references.
The ministry confirms these dates in its official KSeF 2.0 Q&A, including the point that sales documented by NIP receipts do not count toward the PLN 10,000 monthly limit. They are two independent exemptions, not one combined threshold.
The KSeF number in payments: the change most groups underestimate
From 1 January 2027, Article 108g of the VAT Act applies: when a VAT-registered taxpayer pays another VAT-registered taxpayer for a structured invoice, the KSeF number must appear in the transfer reference. The amended Article 108a(3)(3) starts on the same date, extending the same requirement to split payment (MPP). Both are confirmed in the ministry's Q&A.
For a Polish standalone company this is an inconvenience. For a group with shared services, a treasury in another country, or an ERP that generates payment files, it is an integration project. Specifically:
Field length. A KSeF number is long. Check whether your banking portal, payment file format, and ERP remittance field can carry it without truncation.
Collective payments. One transfer covering a dozen invoices uses a collective identifier issued by KSeF. Decide now who generates it and how it reaches whoever releases the payment run.
Exceptions. No KSeF number is required when the invoice was issued in offline or offline24 mode because of an officially announced KSeF failure or unavailability — the number does not exist yet. If the supplier chose offline24 voluntarily and uploaded the invoice the next business day, the number exists and must be quoted.
Payments before a number exists. Prepayments against a proforma, an order, or a payment demand have no KSeF number, because no invoice has been issued yet.
Stored templates. Saved payment templates referencing only a commercial invoice number stop being sufficient.
Nothing here is difficult. All of it is slow, because it crosses AP, treasury, IT, and a bank.
Cash registers and NIP receipts: a retail process that has to be redesigned
Today, a fiscal receipt carrying the buyer's NIP up to PLN 450 gross functions as a simplified invoice on its own. You hand over the receipt and the documentation is complete — issuing a separate invoice would duplicate the document.
That exemption ends on 1 January 2027. An invoice for a business buyer is created in KSeF, small amounts included. The cash register goes back to what it is for: recording retail sales and printing receipts.
One honest caveat: the technical side of cash register operation is meant to be closed by an amendment to the cash register regulation, published by the ministry in June 2026 and scheduled for 1 January 2027. Until it appears in the Journal of Laws it remains a draft. The statutory expiry of Article 145n, by contrast, is already in force in the VAT Act.
Practically: on 2 January a customer gives a NIP on a PLN 180 sale, the register prints a receipt, and someone has to issue a structured invoice. If your current process is "the receipt is enough," it needs to be rebuilt — including who does it and within what deadline.
Penalties: what the ministry said, and what is not law yet
The Ministry of Finance is extending the penalty deferral to 31 December 2027. Four things to understand before you adjust a risk register:
It is an announcement, not a provision. The ministry states plainly that the change requires legislation and that work on the bill is only beginning. Until it passes parliament and is signed, the law still says administrative penalties under Article 106ni apply from 1 January 2027.
The amounts are unchanged. Up to 100% of the VAT shown on an invoice issued outside KSeF, or up to 18.7% of the total amount due on an invoice without VAT. Only the start date moves.
Deferring penalties does not suspend the obligation. The ministry notes that the tax administration will respond to invoices issued outside KSeF (beyond the cases the statute allows) and examine whether bypassing the system leads to incorrect tax settlement.
Ordinary fiscal-penal liability continues. The deferral covers sanctions for failing to use KSeF. Unreliable invoices, refusal to issue an invoice, and understated tax are separate offences and remain punishable throughout.
For a group risk assessment, the accurate line is: 2027 will most likely be another year without financial penalties for technical errors — not a year in which Polish invoices may legally stay outside KSeF.
Readiness checklist for 1 January 2027
Confirm which wave your entity is in. Still relying on the PLN 10,000 monthly exemption? You start issuing in KSeF on 1 January. Already issuing since April 2026? Your work is items 3–6.
Reconcile inbound 2026 invoices. Compare the document count in KSeF against purchase invoices in your ledger. A gap means missing costs and unclaimed input VAT.
Obtain a KSeF certificate. The type 2 certificate is required to issue invoices in special modes (offline24, offline, failure). Without it you cannot invoice when connectivity drops. Valid for two years.
Test offline24 for real. Disconnect, issue an invoice, upload it the next business day, verify both QR codes on the visualisation. This mode is permanent and needs no ministry announcement — treat it as your continuity plan, not an emergency procedure.
Design the "NIP receipt → KSeF invoice" flow if you operate a cash register: owner, deadline, source data.
Open your banking portal and count characters. Will a full KSeF number fit in the reference field? Who issues collective identifiers for multi-invoice payments?
Run one test split-payment transfer against an invoice with a KSeF number — before doing it under a due-date deadline.
Summary
The September announcement removes financial risk for technical errors in 2027, assuming the bill passes in time. It removes no obligations. On 1 January 2027 the exemptions for micro-entities, cash-register invoices and NIP receipts expire, and the KSeF number enters payment references. That leaves 105 days.
Biurko handles issuing, KSeF submission, offline24 and the KSeF number on payment documents in one place — alongside VAT registers and JPK files, because an invoice is where the month starts, not where it ends. The interface is available in English. Start a 14-day free trial at biurko.io and spend December on the target process rather than January on a live one.
FAQ
Has KSeF been postponed to 2028? No. Only the application of administrative penalties is expected to move — the Ministry of Finance announced a deferral until 31 December 2027, which still requires an amendment to the VAT Act. The obligation to issue invoices in KSeF has applied in stages since 1 February 2026 and covers all businesses from 1 January 2027.
Which companies must start issuing KSeF invoices on 1 January 2027? The smallest taxpayers who relied on the transitional exemption for invoiced sales up to PLN 10,000 gross per month (Art. 145m of the VAT Act). That exemption expires on 31 December 2026 and was not covered by the September penalty announcement.
When does the KSeF number become mandatory in bank transfers? From 1 January 2027, for payments between VAT-registered taxpayers for structured invoices (Art. 108g of the VAT Act) and under the split payment mechanism. A single transfer covering several invoices uses a collective identifier issued by KSeF.
What are the penalties for invoicing outside KSeF? Up to 100% of the VAT shown on the invoice, or up to 18.7% of the total amount due where no VAT is shown (Art. 106ni of the VAT Act). The amounts are not changing; the announcement only moves the date from which authorities may apply them.
Does a foreign parent company need a KSeF account? No. The obligation follows the Polish entity that issues the invoice. A foreign group company receives invoices through the channel agreed with the Polish supplier — but any Polish VAT-registered entity in the group must both issue and receive through KSeF.