KSeF and JPK VAT? Changes, penalties, risks

26.01.2026

From 2026, entrepreneurs will face revolutionary changes in VAT settlements. With the launch of the National e-Invoicing System (Krajowy System e-Faktur – KSeF), new obligations related to JPK VAT reporting will also come into force. This means the need to adapt accounting systems, mark invoices with new identifiers, and comply with strict deadlines. Failure to comply with the regulations may result in severe penalties as early as February 2026.

TABLE OF CONTENTS

What is KSeF

KSeF (Krajowy System e-Faktur – National e-Invoicing System) is an ICT system operated by the Ministry of Finance. It enables entrepreneurs to issue, receive, and store structured invoices in electronic XML format. The primary objective of implementing this system is to tighten the tax system and monitor document circulation. It should be noted that mandatory e-invoicing has already been introduced in Italy and Romania, and in 2025 many EU countries also began using this solution.

Stages of KSeF implementation

After numerous analyses related to technical readiness, it has been confirmed that KSeF will be introduced in three stages:

For taxpayers whose sales value for 2024 exceeded PLN 200 million (including VAT) – from 1 February 2026.
For other entrepreneurs not covered by points 1 and 3 – from 1 April 2026.
For the smallest taxpayers whose sales transactions involve small amounts, with total monthly gross sales up to PLN 10,000 – from 1 January 2027.

Importantly, all purchasers must be ready to receive invoices from the KSeF system from 1 February 2026, regardless of when their obligation to issue invoices via KSeF arises.

How KSeF will operate

Issuing an invoice in financial and accounting software,
Sending the invoice to KSeF,
Verifying the invoice’s compliance with all standards, in particular whether it has the correct XML schema,
If the invoice complies with the standards, the system assigns it a unique KSeF number,
The sender receives a generated official confirmation of receipt (UPO) confirming submission of the invoice to the system,
The purchaser receives the invoice.

Offline mode and system failures

In the event of technical issues causing interruptions in the operation of KSeF, it will be possible to issue invoices in offline mode, i.e. outside the system. Once the availability of KSeF is restored, invoices must be submitted within 7 business days (in the case of a system failure) or within 1 business day (in the case of temporary system unavailability). In such cases, the invoice issue date in the system will correspond to the date indicated on the invoice. It is essential that an invoice issued in the taxpayer’s own system has an identical structure and file format to that used in KSeF.

The so-called offline24 mode applies when the taxpayer experiences issues on their own side (e.g. lack of Internet access, software problems) or when delays occur in the operation of KSeF. In such cases, there is 1 business day to submit the invoice to the KSeF system. This situation should be properly documented, although the regulations do not specify exactly how.

Transitional period

For taxpayers whose KSeF implementation date falls in 2026, the legislator has предусмотрed a so-called transitional period lasting until the end of 2026. During this period, taxpayers will not be penalized for errors made when issuing invoices in the KSeF system. The transitional period also exempts taxpayers from the obligation to provide the KSeF number in bank payments, likewise until the end of 2026.

Scope of entities covered

All entrepreneurs registered in Poland are obliged to issue invoices in the KSeF system, regardless of whether they are active or VAT-exempt taxpayers. Invoices issued to foreign customers must also be included in the system.

Taxpayers issuing simplified invoices (i.e. up to PLN 450 gross) and invoices generated via cash registers may continue issuing them as before, but only until the end of 2026. From 1 January 2027, such invoices will also have to be issued through the KSeF system. Invoices issued to flat-rate farmers and to B2C consumers may be issued in KSeF on a voluntary basis.

Foreign taxpayers whose registered office and permanent establishment are not located in Poland are fully exempt from the obligation to use e-invoices. This means that invoices received from foreign contractors will not appear in the system and there will be no obligation to manually enter them into KSeF.

It should also be noted that KSeF will not allow the issuance of documents such as corrective notes, invoice duplicates, or pro forma invoices.

From the taxpayer’s perspective, it is important that KSeF will not verify invoices in terms of substantive correctness, but only in terms of file structure and compliance with system requirements.

Attachments and structured documents

The KSeF system allows for handling attachments, but only structured ones, i.e. in XML format. In order to send structured attachments, it is necessary to report the need to issue and transmit such invoices with attachments in the e-US system, together with justification. Structured attachments will apply, for example, to energy or utilities settlements. Other attachments will have to be sent outside KSeF.

Benefits of implementing KSeF

Implementing KSeF involves not only obligations but also benefits for taxpayers, including:

shortening the VAT refund period from 60 days to 40 days,
storing invoices in the Ministry of Finance database, which prevents loss or damage to documents, as archiving in the system lasts up to 10 years,
facilitating invoice exchange between contractors, which may translate into timely or earlier payments,
simplifications during tax audits, as there will be no obligation to send or deliver documents to tax authorities in paper form,
a single electronic invoice template that will be clearer not only for entrepreneurs’ IT systems but also for accountants,
greater automation of invoice circulation and the ability to use the full potential of e-invoices to automate more processes,
no need to issue duplicate invoices.

Draft amendments concerning reporting – JPK VAT

However, this is not all. The Ministry of Finance has prepared another change for taxpayers.

A draft amendment concerning JPK VAT reporting has been submitted to the Government Legislation Centre in connection with the implementation of KSeF. It includes, among other things, the introduction of new document markings:

OFF – this marking applies to an invoice issued during a KSeF failure, which on the date of submitting the records does not have a system identification number or has not been sent to the system.
BFK – this marking identifies a document for which a KSeF number is not assigned, but which must nevertheless be included in JPK VAT.
DI – this marking refers to a document other than an invoice, as well as invoices issued in offline mode that have not yet been submitted to the KSeF system.

If, on the date of submitting JPK VAT, the taxpayer does not have a KSeF number for a sales invoice, it should be reported with the DI marking. After obtaining the KSeF number, the taxpayer should correct JPK VAT and submit a file in which the invoice is marked with the KSeF number.

New obligations in JPK VAT from 1 February 2026 – marking invoices with the KSeF number

The regulation also introduces an obligation to mark purchase invoices with the KSeF number in the purchase records. This means that all taxpayers, even those who will only become subject to mandatory KSeF in 2026 or 2027, will have to adapt their JPK VAT systems to the new rules from 1 February 2026.

This obligation also applies to foreign entities registered for VAT in Poland, even if they are not required to issue invoices via KSeF.

Penalties for errors in JPK VAT from 1 February 2026

From 1 February 2026, regulations providing for penalties for incorrect markings in JPK VAT records will also come into force.

Pursuant to Article 109(3h) of the VAT Act, if a taxpayer fails to correct errors in the records within 14 days following a request from the authority, the tax office may impose a financial penalty of PLN 500 for each error.

This means that although sanctions for issuing invoices outside KSeF have been postponed until 2027, penalties for errors in JPK VAT will apply already from February 2026.

The regulation also provides for the possibility for sellers to issue transaction confirmations. This applies when an invoice is issued in offline mode and has not been assigned a KSeF number, and the seller wishes to assure the purchaser that the invoice will be issued in KSeF. The transaction confirmation will not be defined in any way by law. The possibility of issuing such confirmations will apply exclusively to domestic transactions.

Currently, the regulation is still in the draft phase; however, it is already clear that revolutionary changes lie ahead.

FAQ

From when does KSeF apply and who does it cover?
KSeF will be mandatory from 1 February 2026 for the largest companies (annual sales exceeding PLN 200 million). From 1 April 2026 it will apply to other entrepreneurs, and from 1 January 2027 to the smallest taxpayers.

Will penalties for errors in KSeF be imposed in 2026?
No. The year 2026 is a transitional period – taxpayers will not be penalized for errors in issuing invoices in KSeF. Sanctions under Article 106ni of the VAT Act will apply only from 1 January 2027.

Can penalties related to JPK VAT still arise?
Yes. From 1 February 2026, penalties may be imposed for errors in JPK VAT records, e.g. incorrect marking of invoices with KSeF identifiers. The penalty amounts to PLN 500 per error.

What are the OFF, BFK, and DI markings in JPK VAT?
These are new identifiers in the records:

OFF – an invoice issued during a KSeF failure,
BFK – a document without a KSeF number that must be included in the records,
DI – a document other than an invoice or one issued offline.

Does the purchaser have to report the KSeF number of a purchase invoice?
Yes. From 1 February 2026, the purchaser is required to provide the KSeF number in the purchase records, even if they themselves are not yet required to issue invoices via KSeF.

Do foreign entities have to use KSeF and JPK VAT?
Foreign entities without a registered office in Poland are exempt from the obligation to issue invoices in KSeF. However, if they are registered for VAT in Poland, they must adapt their JPK VAT reporting from 1 February 2026.

What is a transaction confirmation and is it mandatory?
A transaction confirmation is an informal document confirming a sale, issued before the invoice is submitted to KSeF. It is an auxiliary, voluntary solution, used mainly in B2B retail sales.

Author:

Aleksandra Skrobek, Junior VAT Specialist, MDDP Outsourcing

VAT

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