What is KSeF?
The National e-Invoice System (KSeF) is a system used to issue, send, receive, and store structured invoices. From February 1, 2026, KSeF will gradually cover all entrepreneurs and invoice issuers in Poland. The implementation of KSeF serves to digitize invoicing and accounting processes. It also helps to avoid errors when issuing invoices.
Timeline
Year 2025:
- September 1 KSeF 1.0 test environment shutdown
- September 24 Wednesdays with KSeF – free training
- September 30 KSeF 2.0 API – release on the test environment
- October 15 KSeF 2.0 API – release on the pre-production environment
- November 1 Certificates and Authorizations Module (MCU) – launch
- November 3 KSeF 2.0 Taxpayer Application – release on the test environment
- November 15 KSeF 2.0 Taxpayer Application – release on the pre-production environment
Year 2026:
- January 1 Module for reporting invoices with attachments on e-US – launch
- January 26-31 Technical break in the KSeF 1.0 production environment
- February 1 KSeF 2.0 for large enterprises and invoice recipients
- April 1 KSeF 2.0 mandatory for other enterprises
Year 2027:
- January 1 KSeF 2.0 for previously exempted entrepreneurs (up to PLN 10,000 per month)
Who will be subject to this obligation?
- From February 1, 2026, the obligation to issue invoices in KSeF will apply to the largest entities, i.e., those whose gross sales turnover exceeded PLN 200 million in 2024.
- From April 1, 2026, the obligation to issue invoices will apply to all entities except micro-entrepreneurs.
PLEASE NOTE! RECEIVING INVOICES IN KSEF WILL BE MANDATORY FOR ALL ENTITIES FROM FEBRUARY 1, 2026!
Exemption for micro-entrepreneurs
Micro-entrepreneurs may issue sales invoices outside the KSeF system until the end of 2026, provided that the total value of sales documented by invoices (including VAT) does not exceed PLN 10,000 gross in a given month.
What documents will be issued in KSeF?
Mandatory:
- Sales invoices for business contractors (domestic)
- Sales invoices for business contractors (foreign), i.e.:
- Intra-Community supply of goods (ICS)
- Export of goods
- Export of services
Optional:
- Sales invoices for individuals not conducting business activity
NOTE! Foreign contractors will not have access to the KSeF system. THIS MEANS THAT INVOICES ISSUED IN KSEF FOR FOREIGN RECIPIENTS WILL HAVE TO BE SENT TO THEM IN THE TRADITIONAL WAY – AS BEFORE, E.G., BY EMAIL OR POST.
What will not be covered by KSeF?
- Fiscal receipts with a tax identification number (simplified invoices) – time limit, only until December 31, 2026
- Sales invoices issued according to separate procedures, i.e., IOSS and OSS
- Transport documents, i.e., train tickets, public transport tickets, motorway tolls, which were treated as invoices
How to prepare for KSeF?
1. Process audit
Start by analyzing how invoices are currently issued and received in your company. Check who is responsible for this, what tools you use, and which elements need to be changed.
2. Take care of permissions
Log in to the e-Tax Office and check who in the company has (or should have) access to KSeF. Permissions can be granted to:
- the owner or members of the management board,
- employees,
- the accounting office (after appropriate authorization).
3. Contact your financial, accounting, or sales system provider to:
- confirm that the system is ready to work with KSeF,
- obtain support in clarifying the method of integration with systems (e.g., FK),
- obtain assistance in establishing a connection with the KSeF API,
- and conduct initial tests of invoice transmission.
4. Ensure that your work organization is aligned with KSeF requirements
It is worth adapting the organization of work in the company to the requirements of KSeF, because it is the entrepreneur who bears the main responsibility for issuing invoices in the system. An accounting office can support the implementation process and advise on integration, but it is the client – as the entity issuing invoices – who should actively prepare their procedures and software for the new rules. Well-planned actions on the part of the company will help avoid operational problems after the KSeF obligation comes into force.
5. Establishing rules for cooperation with GLC
It is worth determining who issues invoices and how the documents will be made available to our office.
How can we help you?
GLC specialists are available to provide advice, substantive supervision, and process verification—we will help you prepare organizationally and procedurally for the new obligation.
To facilitate your implementation of KSeF, we are preparing a series of practical educational materials in November and December 2025:
- → Training – a detailed discussion of obligations, granting of authorizations, and receipt of invoices.
- → A series of videos introducing the subject of KSeF, i.e., the obligations and rights of sellers and recipients.
We will provide the training and publication schedule in the second half of October.
