KSeF is the government system through which businesses in Poland will issue and receive invoices. Below we explain, in plain language, what it is, how it works and from when it applies to you — no jargon.
KSeF (Krajowy System e-Faktur, the National e-Invoice System) is a single, central government platform where invoices between businesses are created, exchanged and stored. Instead of sending an invoice by email or by post, you issue it in this system, and your business partner picks it up from the same place.
Think of it as a shared "invoice mailbox" run by the tax office — every invoice lands there automatically, gets a number and is kept safe. A KSeF invoice (a so-called structured invoice) always has the same, orderly format, so any software can read it.
The main goal is to tighten the VAT system and reduce fraud — when every invoice passes through one central government system, fake documents are much harder. At the same time it is meant to make life easier for businesses: no more lost invoices, no manual re-typing and no digging through emails. The state gains transparency, and business owners get one place where all their invoices live.
You create the invoice just as you do now — in your invoicing software or in the portal you use to work with the office.
Instead of sending it yourself, the invoice is passed to the system, which automatically checks that all required fields are there.
The system assigns a unique number and a date — proof that the invoice officially exists. The date it is sent to KSeF counts as the issue date.
Your business partner sees the invoice in KSeF straight away. Nothing needs to be sent or printed.
The system keeps it for 10 years, so you don't have to archive it yourself and you always have access to it.
If you have no internet access, an invoice can be issued in offline mode and sent to KSeF on the next business day — your sale is not blocked.
You don't need to learn government systems. In practice you have several options:
Using KSeF requires authentication (e.g. a Trusted Profile, a qualified signature, a company seal or a token) or an authorisation for the office. The biggest day-to-day change: you no longer email invoices — you view them in the system or in your client portal.
KSeF has been available voluntarily since 2022 — any business can start earlier, before the system becomes mandatory for it. Over time, every business will receive its invoices through KSeF.
Until 31 December 2026 there is a transition period — penalties for mistakes or a missing KSeF invoice are suspended, giving businesses time to prepare calmly.
Invoices to private individuals (B2C) are not issued through KSeF for now — the existing rules apply.
Receipts with a NIP up to PLN 450, treated as simplified invoices, stay outside KSeF.
Foreign entities without a fixed place of business in Poland are not required to use it — they may use KSeF voluntarily.
In practice, mainly the route an invoice takes changes — instead of email and PDF there is one system. Less paper, less manual sending and a lower risk of an invoice getting lost. It does not change your tax form, payment deadlines or VAT rates.
At TaxProfis we support KSeF from day one: the authorisation, sending and receiving of e-invoices, and connecting it to your invoicing software. You issue your invoices as usual, and we make sure everything runs in line with the rules.
Let's talk about KSeF