The mandatory National e-Invoicing System (Krajowy System e-Faktur, KSeF) has been in operation since February 2026, yet in many businesses it is still merely an add-on to the old document workflow. The most common question is: what really has to be ready before 1 January 2027? The answer is short – everything for which the transitional exceptions and the absence of penalties are a substitute until the end of 2026. On 1 January 2027 the exceptions for invoiced sales of up to PLN 10,000 a month and for invoices from cash registers cease to apply and, under the current provisions, penalties begin to apply. From that day, a registered VAT payer paying another registered VAT payer by transfer must also give the KSeF number of the invoice. We set out the timetable, the emergency modes, corrections and the deduction of VAT on invoices from outside the system.
Timetable and exceptions until the end of 2026
The obligation to issue invoices in KSeF now applies, as a rule, to all taxpayers – the only difference between them is how long they may use the transitional exceptions.
Article 106ga(1) of the VAT Act (ustawa o VAT) requires taxpayers to issue structured invoices using KSeF. Article 145l allowed taxpayers whose sales in 2024 did not exceed PLN 200,000,000 (including tax) to issue invoices outside KSeF until 31 March 2026. Article 145m(1) permits this until 31 December 2026 if the sales, including tax, documented by such invoices in a given month do not exceed PLN 10,000. Under paragraph 2, this right is lost “starting from the invoice by which the value was exceeded” (translation by the author). Until the end of 2026, Article 145n(1) permits invoices from cash registers and fiscal receipts treated as invoices.
The Director of the National Revenue Information Service (Dyrektor Krajowej Informacji Skarbowej, the Director of the KIS) quoted the wording of these provisions in an individual tax ruling of 27 October 2025, no. 0112-KDIL1-3.4012.657.2025.2.MR. On 31 March 2026 the Ministry of Finance (Ministerstwo Finansów, MF) explained that once the limit has been exceeded there is no return to the previous rules, even if sales are lower in the following months. The limit does not include sales to consumers, sales recorded on a cash register, receipts showing the buyer’s tax identification number (NIP) of up to PLN 450, or invoices excluded by specific provisions.
Hypothetical example: in May 2026 a taxpayer issues three invoices to businesses outside KSeF, for PLN 6,000, PLN 3,000 and PLN 2,000 gross. After two invoices the total is PLN 6,000 + PLN 3,000 = PLN 9,000, which is within the limit. The third gives PLN 9,000 + PLN 2,000 = PLN 11,000, so the taxpayer now issues that invoice and all subsequent ones in KSeF.
If you rely on Article 145m, calculate your sales cumulatively before each invoice, not after the month has closed.
Timetable of the obligation and the transitional exceptions
| Period | Who is covered | What applies | Legal basis |
|---|---|---|---|
| from 1 February 2026 | taxpayer purchasers | receiving structured invoices in KSeF | Article 106na(3) of the VAT Act; Ministry of Finance announcement of 26 March 2026 |
| from 1 February 2026 | sales in 2024 above PLN 200,000,000 | issuing invoices in KSeF | Articles 106ga(1) and 145l of the VAT Act |
| from 1 April 2026 | other taxpayers issuing invoices | issuing invoices in KSeF | Article 106ga(1) of the VAT Act |
| 1 April – 31 December 2026 | invoiced sales of up to PLN 10,000 gross per month | invoices outside KSeF until the limit is exceeded | Article 145m(1) and (2) of the VAT Act |
| 1 February – 31 December 2026 | sales at cash registers | invoices from cash registers and receipts showing the buyer’s NIP treated as invoices | Article 145n(1) of the VAT Act |
| from 1 January 2027 | all taxpayers | end of the exceptions, statutory penalties, KSeF number in transfers | Articles 106ga(1) and 108g of the VAT Act; Article 17(2) of the Act of 16 June 2023 |
Who issues invoices in KSeF and who may issue them outside it
The exclusions from KSeF form a closed statutory catalogue and – apart from the exemption under Article 113a – do not cover VAT-exempt sales.
Article 106ga(2) of the VAT Act excludes from the obligation invoices issued by a taxpayer without its seat of business activity in Poland that has no fixed establishment here or whose fixed establishment does not participate in the transaction. It also excludes invoices under the special schemes in Chapters 7, 7a and 9 of Division XII and invoices issued to a natural person not carrying on business activity. The exclusion further covers the cases set out in the regulation issued under Article 106s and a taxpayer exempt under Article 113a(1). In those cases electronic or paper invoices are issued (paragraph 3), while KSeF may be used voluntarily for consumers and by foreign issuers (paragraph 4). According to the tax explanatory notes of 28 January 2026, a fixed establishment is determined in the same way as for VAT purposes, and it participates in a transaction where its staff and facilities serve the supply of goods or services, not merely invoicing.
A taxpayer covered by the small-business exemption does not stand outside the system. In the ruling cited above, the authority stated that “KSeF covers only structured invoices and does not apply to other sales documents, such as bills”. It added the proviso, however, that “at the purchaser’s request, you will be obliged to issue a structured invoice”.
According to the Ministry of Finance, an invoice for a consumer (B2C) may be issued in KSeF voluntarily, but it is handed over to the purchaser in the agreed manner, for example as a printout or a file with a QR code. The date of receipt of such an invoice is then taken to be the date on which it is actually received (Article 106na(4)).
Mark in your counterparty data whether the recipient is a domestic taxpayer, a foreign entity or a consumer – the invoice channel depends on it.
Offline modes, unavailability and failure – deadlines for subsequent submission
The Act provides for four situations in which an invoice is issued without a live connection to KSeF and, for each of them, separately governs the sending of the invoice and its date of receipt.
An offline24 invoice is sent “without delay, no later than on the next working day after the day of its issue” (Article 106nda(2)). A structured invoice sent later than the date indicated on it is treated in the same way (Article 106nda(16)). A further failure announced during the period for subsequent submission of invoices moves the start of that period (Article 106nf(5)).
Modes of issuing invoices without a live connection to KSeF
| Mode | Deadline for sending to KSeF | Date of receipt by the taxpayer purchaser | Legal basis |
|---|---|---|---|
| offline24 | no later than the next working day after the day of issue | the day the KSeF number is assigned | Article 106nda(2), (10), (11) and (16) of the VAT Act |
| KSeF unavailability (Article 106ne(4)) | no later than the next working day after the unavailability ends | the day the KSeF number is assigned | Article 106nh(1), (2) and (4) of the VAT Act |
| KSeF failure (announcement under Article 106ne(1)) | 7 working days from the end of the failure as indicated in the announcement | the day of actual receipt, at the latest the day the number is assigned | Article 106nf(4), (5) and (10) of the VAT Act |
| announcement under Article 106ne(3) (total failure) | no obligation to send | the day of actual receipt under the general rules | Articles 106nf(7) and 106nh(3)(2) of the VAT Act |
The authority treats offline24 as an everyday solution: “the so-called offline24 mode is a mode that may be used by taxpayers on a day-to-day basis” (ruling of 20 March 2026, no. 0112-KDIL1-3.4012.932.2025.1.KM). The date of issue is determined by field P_1 of the invoice file: “In the case of invoices issued in the offline24 modes, to which Article 106nda of the Act refers, the date of issue of the invoice is always the date indicated by the taxpayer on that invoice in field P_1” (ruling of 30 January 2026, no. 0114-KDIP1-1.4012.1006.2025.1.KOM). The Ministry of Finance points out that in offline24 mode and during unavailability the invoice is not handed over to the purchaser before it is sent to KSeF – the exception is emergency mode.
Write down a procedure: who activates the mode, where the invoices wait, and who monitors the deadline for subsequent submission and the Ministry of Finance announcements.
An invoice from outside KSeF and the deduction of VAT
An invoice issued in breach of the KSeF obligation does not deprive the purchaser of the right to deduct, but the timing of that right depends on the mode in which the invoice was issued.
The right to deduct derives from Article 86(1) of the VAT Act and arises in the period in which the tax becomes chargeable, but not earlier than in the period in which the invoice is received (paragraphs 10 and 10b(1)). The negative conditions in Article 88(3a) do not concern the channel through which the invoice is issued.
In a ruling of 20 October 2025, no. 0114-KDIP1-3.4012.739.2025.1.AMA, the authority stated: “Issuing the Purchase Invoices without using the National e-Invoicing System, contrary to the obligation, does not deprive you of the right to deduct input VAT, since this does not constitute a negative condition, listed in Article 88 of the Act, that precludes the deduction of that tax”. The authority did not confine this assessment to the transitional period and, after the obligation took effect, repeated it in a ruling of 6 May 2026, no. 0111-KDIB3-1.4012.204.2026.2.WN. It regarded the date of actual receipt of the invoice as the moment of deduction and added: “Any subsequent issue in KSEF of an invoice documenting the same transaction will, by contrast, remain irrelevant to the creation and exercise of the right to deduct VAT”. That date fixes a payment deadline counted from delivery, and with it the running of the 90 days under Article 89b(1).
The position is different where the supplier issues an invoice either in offline24 mode or during KSeF unavailability and hands over its visualisation before sending it to the system. In that case the authority held: “In the case under analysis, the date on which the KSeF number was allocated to the invoice should be taken as the moment of receipt of that invoice” (ruling no. 0112-KDIL1-3.4012.932.2025.1.KM). Receipt outside KSeF becomes decisive only where the supplier does not send the invoice to the system at all. You report a late deduction in one of the next three periods or, with quarterly settlement, in one of the next two (Article 86(11)).
The authority may argue that “in principle, the use of invoices outside KSeF should be the exception” (ruling of 6 May 2026), and the Ministry of Finance has announced that in 2027 the National Revenue Administration (Krajowa Administracja Skarbowa, KAS) will examine whether not using the system leads to unreliable settlements. This argument does not remove the right to deduct, because restrictions must derive from an express provision, and Article 88 contains no such condition. It does, however, determine that the document must reflect the actual transaction and contain the data required by Article 106e.
In a ruling of 30 April 2025, no. 0111-KDIB3-2.4012.88.2025.1.MGO, the authority – citing the judgment of the Court of Justice of the European Union in Case C-518/14 – held that possession of an invoice containing the data required by the VAT Directive is a formal requirement, not a substantive condition.
Keep a register of purchase invoices from outside KSeF, recording the channel and the date of actual receipt. Do not adjust the deduction when the supplier later sends such an invoice to the system.
Invoice corrections in KSeF
A structured invoice is corrected in KSeF by an invoice stating the KSeF number of the original invoice, and a correction for a discount or a return takes effect, as a rule, in the period in which it is issued.
A corrective invoice contains the KSeF number of the invoice being corrected, unless the original invoice does not have one (Article 106j(2)(2a)). Under Article 106j(4), “A corrective invoice correcting a structured invoice is issued in the form of either a structured invoice or an invoice referred to in Article 106nda(1)”. The tax base is reduced for the reasons set out in Article 29a(10)(1)–(3) for the period in which the corrective invoice is issued in the form of a structured invoice (Article 29a(13)). An offline or emergency invoice is corrected only after it has been assigned a KSeF number (Articles 106nda(12) and 106nf(11)).
The most significant problem in practice is an incorrect purchaser NIP. In a ruling of 23 June 2026, no. 0113-KDIPT1-2.4012.434.2026.1.AJB, the authority observed: “This is because the system does not check the correctness of the counterparty’s data”. The invoice then reaches the wrong recipient. The authority accepted as correct a correction to zero and “the issue of a new structured invoice to the Counterparty with the correct NIP” – both in the period of the original invoice. The problem recurs when the recipient’s NIP changes, for example after the conversion described in the article Converting a sole trader into a sp. z o.o. — what actually happens to the tax position. The Ministry of Finance also warns against issuing an invoice already issued outside KSeF again in the system, because this creates two invoices for a single sale.
Introduce a block on re-sending an invoice issued outside KSeF and a rule of correction to zero where there is an error in the purchaser’s data.
Authorisations, certificates and the purchase invoice workflow
Access to KSeF is assigned to persons and entities within a defined scope, and without authorisations and certificates a business cannot issue an offline invoice or receive its purchase invoices on time.
The detailed rules are laid down in the regulation on the use of KSeF. According to the Ministry of Finance announcement of 31 March 2026, the ZAW-FA notification is filed, before the system is first used, by an entity that is not a natural person and does not have a qualified electronic seal. It is filed either on paper or through e-Urząd Skarbowy [the tax administration’s online service]. Authorisations, for example for an accountant or an accounting firm, are granted in the system, and self-billing requires the purchaser to hold an authorisation to issue invoices on behalf of the seller. A type 1 certificate is used for authentication, and a type 2 certificate for invoices in offline and emergency modes and for the QR code; it is valid for no more than 2 years. The obligation to obtain a certificate for offline invoices follows from Article 106nda(7) of the VAT Act.
On the purchase side, Article 106na is decisive: a structured invoice is issued on the day it is sent to KSeF (paragraph 1) and received on the day its number is assigned (paragraph 3), irrespective of when the business downloads it. That date determines the deduction period.
Review authorisations by role, enter the certificate expiry dates in your calendar and download purchase invoices from KSeF every day.
What changes on 1 January 2027
On 1 January 2027 the transitional facilitations end, the statutory penalties begin to apply, and the KSeF number in payments is added to the obligations.
The exceptions in Articles 145m and 145n apply until 31 December 2026. From 1 January 2027 the smallest taxpayers also use KSeF, and an invoice for a taxpayer issued at a cash register is subject to the general rule in Article 106ga(1). Under the current provisions, penalties for breaches of KSeF-related obligations apply from that day; no penalties are imposed in 2026.
On 16 September 2026 the Ministry of Finance announced an extension of the deferral of penalties until 31 December 2027, and according to press reports a bill providing for such a statutory amendment was published on 23 September 2026. The bill has no legal effect – until the act is passed and promulgated, the provisions described above apply and the authority will rely on them. The Ministry of Finance also announced that, even if penalties are deferred, KAS will respond to invoices issued outside KSeF where no statutory exception applies.
Until 31 December 2026 the KSeF number in the transfer reference is not mandatory. From 1 January 2027 that number – or the collective identifier – is given by a registered VAT payer paying another registered VAT payer. This covers payments for structured invoices and for invoices issued in offline24 mode or during KSeF unavailability, including where the payer pays on behalf of the purchaser (Article 108g(1)). The obligation applies to a transfer and to any other instrument with a transfer reference. For a direct debit it rests with the invoice issuer (paragraph 2), and the recipient’s status is determined on the basis of the register of VAT taxpayers (wykaz podatników VAT, the “white list”) as at the payment date (paragraph 3). The start date follows from Article 17(2) of the Act of 16 June 2023: “The provision of Article 108g of the act amended in Article 1 applies to payments made from 1 January 2027”. In a ruling of 8 July 2026, no. 0111-KDIB3-1.4012.306.2026.2.MG, the authority framed the obligation narrowly: “The provision of Article 108g of the Act on the tax on goods and services states expressly that its application relates only to payments for invoices for the supply of goods or the supply of services”.
An act amending the VAT Act, which also includes changes to the split payment mechanism (mechanizm podzielonej płatności), was promulgated in the Journal of Laws on 29 September 2026. Until it enters into force, the provisions described above apply.
Plan for the payment module to retrieve the KSeF number or the collective identifier and to check the recipient’s status in the register as at the payment date.
The most common mistake
The most common mistake is to treat the penalty-free year as time for decisions and to put off rebuilding authorisations, the purchase invoice workflow and bookkeeping until the last quarter of 2026.
The effect becomes apparent in January 2027, because several changes take effect at the same time. From that day, a taxpayer relying on Article 145m or Article 145n issues all invoices to businesses in KSeF. The payments team needs the KSeF number of invoices paid to registered VAT payers, so the purchase ledger must store it and pass it on to the transfer. The deduction depends either on the date on which the number was assigned or on the date of actual receipt, so the accounting team must distinguish invoices by channel. The announcement of a deferral of penalties does not postpone any of this.
How to avoid it: no later than October 2026, draw up a list of changes with an owner and a deadline for each of them – authorisations and certificates, the offline modes procedure, the register of invoices from outside KSeF, the daily import of purchases and the payment module. Test everything on December invoices, not January ones.
Summary
- Check whether you rely on Article 145m or Article 145n of the VAT Act and, before 1 January 2027, prepare to issue all your invoices in KSeF.
- Describe the procedure for offline24 mode, unavailability and failure, with the deadlines for sending invoices and the persons responsible.
- Deduct VAT on invoices from outside KSeF according to the date of their actual receipt and, on offline24 invoices and invoices issued during KSeF unavailability that were handed over outside the system, according to the date on which the KSeF number was assigned.
- Put authorisations, the ZAW-FA notification and certificates in order, and download purchase invoices from KSeF every day.
- Change the payment process so that, from 1 January 2027, a transfer to a registered VAT payer contains either the KSeF number or the collective identifier.
Sources cited
All quotations from Polish-language sources — statutes, tax rulings and court judgments — are given here in the author's translation; the Polish wording is authoritative.
- Individual tax ruling of the Director of the National Revenue Information Service of 20 October 2025, no. 0114-KDIP1-3.4012.739.2025.1.AMA – the right to deduct VAT on invoices issued and received outside KSeF contrary to the obligation; no such condition in Article 88 of the VAT Act. https://eureka.mf.gov.pl/informacje/podglad/662633
- Individual tax ruling of the Director of the National Revenue Information Service of 6 May 2026, no. 0111-KDIB3-1.4012.204.2026.2.WN – deduction of VAT on an invoice from outside KSeF in the period of its actual receipt, with no adjustment after it is later sent to the system; the running of the period under Article 89b(1). https://eureka.mf.gov.pl/informacje/podglad/690059
- Individual tax ruling of the Director of the National Revenue Information Service of 20 March 2026, no. 0112-KDIL1-3.4012.932.2025.1.KM – the moment of deduction for invoices from outside KSeF, for offline24 invoices and invoices issued during unavailability (the date on which the number is assigned) and for invoices issued in emergency mode. https://eureka.mf.gov.pl/informacje/podglad/683572
- Individual tax ruling of the Director of the National Revenue Information Service of 30 April 2025, no. 0111-KDIB3-2.4012.88.2025.1.MGO – an invoice issued to a different entity gives the right to deduct only after correction by the seller; possession of an invoice containing the data required by the VAT Directive as a formal requirement for deduction. https://eureka.mf.gov.pl/informacje/podglad/637465
- Individual tax ruling of the Director of the National Revenue Information Service of 30 January 2026, no. 0114-KDIP1-1.4012.1006.2025.1.KOM – an invoice sent to KSeF on the next working day as an offline24 invoice, with the date of issue taken from field P_1. https://eureka.mf.gov.pl/informacje/podglad/677466
- Individual tax ruling of the Director of the National Revenue Information Service of 27 October 2025, no. 0112-KDIL1-3.4012.657.2025.2.MR – a taxpayer covered by the small-business exemption: a bill outside KSeF and, at the purchaser’s request, a structured invoice. https://eureka.mf.gov.pl/informacje/podglad/664453
- Tax explanatory notes of 28 January 2026 on the rules for determining a fixed establishment in Poland for the purposes of issuing invoices using the National e-Invoicing System – the fixed establishment of a foreign taxpayer and its participation in the transaction as conditions for exclusion from KSeF (Article 106ga(2)(1) and (2) of the VAT Act). https://www.gov.pl/attachment/8fde481a-18aa-4b1b-843e-5bbd303d6f94
- Individual tax ruling of the Director of the National Revenue Information Service of 23 June 2026, no. 0113-KDIPT1-2.4012.434.2026.1.AJB – an incorrect purchaser NIP on a structured invoice: correction to zero and a new invoice in the period of the original invoice. https://eureka.mf.gov.pl/informacje/podglad/697132
- Individual tax ruling of the Director of the National Revenue Information Service of 8 July 2026, no. 0111-KDIB3-1.4012.306.2026.2.MG – the scope of the obligation to give the KSeF number in a transfer (Article 108g of the VAT Act) and the date from which it applies. https://eureka.mf.gov.pl/informacje/podglad/699592
- Judgment of the Court of Justice of the European Union in Case C-518/14 – possession of an invoice containing the data under Article 226 of Directive 2006/112 as a formal requirement, not a substantive condition of the right to deduct; judgment cited in the individual tax ruling of the Director of the National Revenue Information Service of 30 April 2025, no. 0111-KDIB3-2.4012.88.2025.1.MGO. https://eureka.mf.gov.pl/informacje/podglad/637465
- Ministry of Finance announcement of 31 March 2026 “What you should know before the start of stage II of the implementation of the National e-Invoicing System” (Co warto wiedzieć przed startem II etapu wdrożenia Krajowego Systemu e-Faktur) – the PLN 10,000 limit, offline and emergency modes, ZAW-FA, authorisations, certificates, B2C invoices. https://www.gov.pl/web/finanse/co-warto-wiedziec-przed-startem-ii-etapu-wdrozenia-krajowego-systemu-e-faktur
- Ministry of Finance announcement of 26 March 2026 “The second stage of the implementation of the National e-Invoicing System” (Drugi etap wdrożenia Krajowego Systemu e-Faktur) – the stages of the obligation and no sanctions for 2026. https://www.gov.pl/web/finanse/drugi-etap-wdrozenia-krajowego-systemu-e-faktur
- Ministry of Finance announcement of 16 September 2026 “Extension of the deferral of penalties for errors in the use of KSeF until the end of 2027” (Przedłużenie odroczenia kar za błędy w stosowaniu KSeF do końca 2027 r.) – announcement of a statutory amendment and of KAS action in 2027. https://www.gov.pl/web/finanse/przedluzenie-odroczenia-kar-za-bledy-w-stosowaniu-ksef-do-konca-2027-r
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As a tax advisor I take care of the substantive quality of our free materials. My aim is to educate the market through reliable analyses that allow entrepreneurs to apply the law safely in practice.
Get in touch →Legal basis: Act of 11 March 2004 on the tax on goods and services (consolidated text: Dz.U. z 2025 r. poz. 775, as amended): Article 2(31), (32) and (32a), Article 29a(10)(1)–(3) and (13), Article 86(1), (10), (10b)(1) and (11), Article 88(3a), Article 89b(1), Article 99(2) and (3), Article 106b(3), Article 106e(1) and (5)(3), Article 106ga(1)–(4), Article 106j(2)(2a) and (4), Article 106na(1), (3) and (4), Article 106nda, Article 106ne(1), (3) and (4), Articles 106nf and 106nh, Article 108g(1)–(4), Article 145l, Article 145m(1) and (2), Article 145n(1); Act of 5 August 2025 amending the Act on the tax on goods and services and the Act amending the Act on the tax on goods and services and certain other acts (Dz.U. z 2025 r. poz. 1203) – the dates for implementing mandatory KSeF and the date from which penalties apply; Act of 16 June 2023 amending the Act on the tax on goods and services and certain other acts: Article 17(2); Regulation of the Minister of Finance and Economy of 12 December 2025 on the use of the National e-Invoicing System (Dz.U. z 2025 r. poz. 1815, as amended) – authentication, authorisations and certificates in KSeF.