How to issue a KSeF invoice for free: Aplikacja Podatnika step by step

You can issue a KSeF invoice for free in the Ministry of Finance's Aplikacja Podatnika KSeF at ap.ksef.mf.gov.pl: log in, choose "Wystaw fakturę VAT" (issue a VAT invoice), fill in the short form and click "Wyślij do KSeF" (send to KSeF). The invoice counts as issued on the day it is sent to the system and gets a KSeF number once accepted (art. 106na ust. 1 of the VAT Act, ustawa o VAT).

Law as of 14 October 2026.

The app runs in a browser (Chrome, Firefox, Edge, Safari), needs no installation or fee, and lets you issue, receive and download invoices in the FA(3) structure. The steps below follow version 2.6 of the Ministry's user manual from August 2026. The app is in Polish, so the button names are given in Polish with an English gloss.

Three free Ministry of Finance tools

A sp. z o.o. therefore uses the Aplikacja Podatnika or the mobile app. e-mikrofirma is for sole traders only.

Before you start: access to KSeF

1. JDG: the owner has owner permissions automatically and logs in under their own NIP.
2. A company with a qualified seal carrying the company's NIP logs in with that seal and has default owner permissions.
3. A company without a seal files a ZAW-FA notification with the tax office naming one natural person. That person logs in with their own Profil Zaufany or signature and grants further permissions in the app (menu "Nadaj uprawnienie", grant a permission).

Company permissions are explained in KSeF for a sp. z o.o.. Who may use KSeF is set by art. 106nb of the VAT Act.

Logging in to the Aplikacja Podatnika step by step

1. Enter ap.ksef.mf.gov.pl in your browser.
2. Choose how to log in:
   • "Zaloguj przez login.gov.pl" (log in via login.gov.pl): Profil Zaufany, the mObywatel app, online banking or an e-ID card. A foreign eID does not work.
   • "Zaloguj certyfikatem" (log in with a certificate): state whether the certificate carries a NIP or PESEL, click "Pobierz żądanie autoryzacyjne" (download the authorisation request), sign the file with a qualified signature or seal and add it as an .xml or .xades file.
3. Choose the login context "NIP podmiotu" (entity NIP), enter the company's NIP (or your own as a JDG) and click "Przejdź dalej" (continue).

After login the menu on the left shows "Wystaw fakturę VAT", "Wczytaj fakturę" (upload an invoice), "Lista faktur" (invoice list), "Historia sesji" (session history), permissions, tokens and certificates. After a period of inactivity the app logs you out.

Issuing an invoice in the short form

The short form ("Tryb skrócony") is a one-screen form for ordinary domestic sales. The extended form ("Tryb rozszerzony") has every FA(3) field and is needed for advance invoices, corrections, foreign sales and third parties, among others.

1. In the menu click "Wystaw fakturę VAT" and choose "Tryb skrócony".
2. Invoice details: enter the invoice number from your series, the date of supply or service, optionally the payment due date and method (with a bank account for transfers), choose net or gross prices and the currency. The issue date is filled in automatically as today and cannot be changed.
3. Identification data: enter the seller's and buyer's details by hand or fetch them with "Pobierz dane" (fetch data) from the tax ID. For the buyer choose NIP or "Brak identyfikatora" (no identifier), for example for a consumer.
4. Items: name of the goods or service, quantity, unit, unit price and VAT rate (23%, 8%, 5%, 4%, exempt, 0% domestic). The app calculates the values and the rate summary. "Dodatkowe kolumny" (additional columns) adds GTU, PKWiU or CN codes.
5. Annotations, where relevant: VAT exemption with its legal basis (for example art. 113 ust. 1 of the VAT Act), split payment ("mechanizm podzielonej płatności"), cash accounting ("metoda kasowa").
6. Other information on the invoice: footer, KRS number, REGON, BDO, additional description.
7. Under "Pozostałe akcje" (other actions) choose "Podgląd" (preview) and check the invoice.
8. Click "Wyślij do KSeF". After a successful validation the app shows the KSeF number (button "Kopiuj", copy).

The elements every invoice must contain are listed in art. 106e ust. 1 of the VAT Act. The form enforces required fields but cannot tell whether the rate or exemption you chose is correct.

Example

A sp. z o.o., an active VAT payer, issues an invoice on 14 October 2026 for two days of training for a company in Kraków:

The total amount due is 3,690.00 zł. The invoice does not exceed 15,000 zł, so the split payment annotation is not needed (art. 106e ust. 1 pkt 18a of the VAT Act applies only above 15,000 zł and to goods or services in Annex 15). After "Wyślij do KSeF" the invoice has an issue date of 14 October 2026 and its own KSeF number.

Uploading a ready XML file

If you prepare invoices in another program or in the free KSeF invoice generator, you can send just the file:

1. In the menu click "Wczytaj fakturę", then "Dodaj plik" (add file), and choose an XML file in the FA(3) structure.
2. If the file is valid, click "Wystaw fakturę" (issue invoice). You can also choose "Edytuj" (edit), "Podgląd faktury" (preview) or "Usuń" (delete).
3. A file with validation errors can be fixed by editing; sending stays blocked until the errors are gone. A file that does not follow the FA(3) structure is not accepted at all.

An XML file is not yet an invoice. It becomes one on the day it is sent to KSeF (art. 106na ust. 1 of the VAT Act).

Downloading the PDF and UPO

• Invoice as PDF or XML: in "Lista faktur" tick 1 to 10 invoices and open "Pobierz" (download). Several invoices are saved as a ZIP archive, each file named after its KSeF number.
• UPO (official confirmation of receipt): in "Historia sesji" open the session and download the UPO for an invoice from its menu as XML or PDF. A collective UPO for the whole session is available only after the session is closed.
• Invoice for a customer outside KSeF: a consumer or a foreign buyer gets the invoice in an agreed way, for example as a PDF, with a QR code that leads to the invoice in KSeF (art. 106gb ust. 4 and 5 of the VAT Act).

Anyone with the KSeF number, the invoice number, the buyer's identifier and name and the amount due can find the invoice without logging in, using "Wyszukaj fakturę" (find invoice) on the start page.

Purchase invoices

In "Lista faktur" open the tab "Faktury zakupowe (Podmiot2)" (purchase invoices). Filters narrow the list by seller NIP, number, date and amount. An invoice counts as received on the day KSeF assigns its number (art. 106na ust. 3 of the VAT Act), and the system sends no notifications, so check the tab regularly.

A suspicious invoice from an unknown seller can be reported to the tax administration (KAS) with "Zgłoszenie nadużycia" (report abuse) in the invoice preview.

Correction invoice

1. Choose "Wystaw fakturę VAT", then "Tryb rozszerzony", and in "Wskaż rodzaj faktury" (invoice type) choose "Korygująca" (correction).
2. Enter the reason for the correction, the issue date and number of the corrected invoice and, if it was in KSeF, its KSeF number (art. 106j ust. 2 pkt 2a of the VAT Act).
3. Fill in the items that change (the items section is optional in a correction) and issue the invoice.

A wrong buyer NIP cannot be fixed with a data correction. According to the Ministry's manual you issue a correction to zero and a new invoice with the right NIP.

Practising without tax consequences

The Ministry offers two versions for practice:

Data in both versions is deleted periodically. Every invoice sent in the production version is a legal document.

Limits of the free tools

• The app does not keep the company's books or VAT records. Purchase invoices must be downloaded and passed to the accountant or the accounting program.
• You can download at most 10 invoices at a time.
• Invoices sent to KSeF are stored in the system for 10 years from the end of the year of issue (art. 112aa ust. 1 of the VAT Act), so you do not need to archive them separately.

With more invoices, an accounting program can fetch them from KSeF automatically. Norman imports purchase invoices from KSeF and matches them to bank transactions.

Frequently asked questions

Is the Aplikacja Podatnika KSeF really free?

Yes. It is a Ministry of Finance tool, available in the browser at ap.ksef.mf.gov.pl at no cost.

Can I issue an invoice with an earlier issue date?

Not online. The issue date is the day the invoice is sent to KSeF (art. 106na ust. 1 of the VAT Act). The date of supply or service is entered separately.

How does a sp. z o.o. without a qualified seal log in for the first time?

It files a ZAW-FA with the tax office naming one natural person. That person logs in with their own Profil Zaufany or signature under the company's NIP and grants permissions to others.

Does the customer have to accept the invoice in KSeF?

No. The invoice counts as received on the day KSeF assigns its number (art. 106na ust. 3 of the VAT Act), without any acceptance.

Can I practise first?

Yes. The test version (ap-test.ksef.mf.gov.pl) accepts fictitious data, and the Demo version (ap-demo.ksef.mf.gov.pl) needs a real login, but its invoices have no tax effect.