KSeF
Articles on KSeF from the Profais knowledge base.
KSeF 2.0 – company obligations in 2026: a complete guide
From 1 February 2026 the National e-Invoice System is mandatory for the largest VAT payers, and from 1 April for all the others – including those exempt from VAT. The article explains exactly who is covered, from when penalties apply and what to do if you are not yet ready.
e-Delivery 2026 – how to set up an address and why it is mandatory
e-Delivery is the electronic equivalent of a registered letter. When it is mandatory, how to set up a free address on biznes.gov.pl, and what happens to summonses sent by post.
KSeF outage – offline mode and the emergency procedure
What to do when the KSeF system does not respond. The four situations provided for in the act: offline24 mode, unavailability, an outage announced by the Ministry of Finance and a total failure – with the deadlines for sending the invoice and the QR codes.
Corrective invoices and correction notes in 2026 – which to use when
When to issue a corrective invoice and when a note is enough – the procedure, recording in JPK, and the rules under KSeF 2.0.
KSeF in an accounting firm – what permissions to give your bookkeeper
How to grant permissions in KSeF 2.0 to an accounting firm and its staff, how to authenticate, and how to revoke access when you change accounting firm.
How to issue an invoice correctly in 2026 – the mandatory elements
Date of sale vs date of issue, NIP, address, VAT rates, the advance invoice – a practical guide to issuing invoices in KSeF 2.0.
How to issue your first invoice in KSeF: step by step
From logging in to the KSeF panel, through choosing a system, to the acceptance of the KSeF number. A practical guide for a company issuing in KSeF for the first time.
KSeF for beginners – what it is and who it affects
The National e-Invoice System explained for people who have never come across it. How it works, why it was created, and what it changes in everyday work.