What is KSeF?
The National e-Invoice System is a central government system for issuing and receiving invoices in a structured format (XML). Each invoice is sent to the servers of the Ministry of Finance and receives a unique KSeF number. The recipient does not receive the invoice by email or post – they download it from the system.
Key rules
- Structured invoice = XML file in FA(3) format compliant with the MF schema
- Each invoice receives a unique KSeF number – required for payments from 01.01.2027
- An invoice is considered delivered at the moment the KSeF number is assigned – it does not need to be sent separately
- Invoices cannot be canceled in KSeF – the only way is to issue a corrective invoice
- The system operates 24/7 – you can issue invoices at any time
Implementation schedule
February 1, 2026
Obligation for large companies (revenue over 200 million PLN) and foreign entities registered as VAT taxpayers in Poland
April 1, 2026
Obligation for other active VAT taxpayers (small and medium enterprises)
By the end of 2026
Protection period – no penalties for errors in structured invoices
January 1, 2027
Obligation for micro-enterprises and taxpayers exempt from VAT (subjectively and objectively)
January 1, 2027
KSeF number required in the title of the transfer for payments for invoices
Who is affected and when?
| Type of taxpayer | From when is the obligation |
|---|---|
| Large companies (revenue >200 million PLN) | February 1, 2026 ✅ |
| Foreign entities with VAT PL | February 1, 2026 ✅ |
| Other active VAT taxpayers (SMEs) | April 1, 2026 ✅ |
| Micro-enterprises (active VAT) | January 1, 2027 |
| Exempt from VAT (subjectively) | January 1, 2027 |
| Exempt from VAT (objectively) | January 1, 2027 |
| Flat-rate farmers | January 1, 2027 |
What is not issued in KSeF?
- Consumer invoices (B2C) – to individuals not conducting business
- Tickets (transport, highways, parking)
- Invoices from cash registers (receipts with NIP up to 450 PLN)
- Documents from VAT-MOSS/OSS (sales to EU consumers)
What to watch out for – KSeF traps
No possibility of cancellation
Issued an invoice with an error? You cannot cancel it. The only option is to issue a corrective invoice, also through KSeF. This is a change from previous practice, where it was possible to cancel an invoice before its delivery.
KSeF number in the transfer (from 01.01.2027)
From January 2027, the KSeF number of the invoice must be provided in the title of the transfer. Lack of KSeF number = risk that the payment will not be settled by authorities under the split payment mechanism.
Moment of delivery
An invoice is considered delivered at the moment the KSeF number is assigned – regardless of whether the recipient has downloaded it. The payment deadline starts from that moment.
System failure
The Ministry of Finance has published procedures in case of KSeF failure. In the event of system unavailability, an invoice can be issued outside KSeF and entered after access is restored within 7 working days.
What to do to be prepared?
- Check your invoicing software – does it support KSeF (most accounting programs have already added this feature)
- Obtain an authorization token in the application ksef.mf.gov.pl (via Trusted Profile or qualified signature)
- Issue a few test invoices – in the KSeF test environment (ksef-test.mf.gov.pl)
- Inform your contractors – that from the date of your obligation, invoices will be available only in KSeF
- Plan the workflow – who issues, who receives, how to archive
Tools for KSeF
- KSeF Taxpayer Application – free tool from the Ministry of Finance
- KSeF Test Environment – for learning and testing
- Commercial programs: Fakturownia, iFirma, Wfirma, inFakt, Comarch ERP – most have KSeF integration
Comments (0)
No comments yet. Be the first!