What "logging in" to KSeF actually means
KSeF (Krajowy System e-Faktur) is the government platform that all structured invoices in Poland flow through. To do anything in it — issue an invoice, view purchase invoices, grant access to your accountant — you must authenticate: prove to the system that you're authorized to act on behalf of a specific NIP.
Several methods exist: Profil Zaufany, a qualified electronic signature, a qualified seal (for companies), a KSeF certificate, and tokens for software integrations (tokens remain valid until the end of 2026). The Ministry of Finance lists them all in its official KSeF 2.0 Q&A.
Profil Zaufany is free, requires no extra software, and most people running a business in Poland already have one — it's the same profile used for ZUS (social insurance) and the e-Tax Office. That makes it the default choice for JDG owners (JDG = jednoosobowa działalność gospodarcza, a Polish sole proprietorship).
Before your first login: a 3-item check
An active Profil Zaufany. Not sure you have one? Try logging in at pz.gov.pl. If you don't, you can create one in minutes through Polish online banking. Foreign founders without a PESEL number should note: Profil Zaufany requires one, so directors without PESEL typically authenticate via a qualified signature instead.
Your company's NIP. KSeF will ask for it right away — it's how the system knows whose invoices you want to work with.
Access to your confirmation method — your Polish banking app, SMS codes, or the mObywatel app, depending on how you confirm Profil Zaufany operations.
Good news for sole traders: no application forms. KSeF automatically grants full owner-level rights to a JDG owner because your PESEL is linked to the business NIP. Paperwork (the ZAW-FA form) is mainly a concern for companies that don't hold a qualified seal — details on the official KSeF portal.
The login flow, step by step
Step 1. Open the KSeF 2.0 Taxpayer Application
Go to https://ap.ksef.mf.gov.pl/web/. Check that the domain ends in mf.gov.pl — that's the Ministry of Finance. It runs in the browser; there's nothing to install.
Step 2. Choose your context — enter the NIP
The system asks on whose behalf you want to act. Enter your company's NIP. If you manage several entities (your own JDG plus a company, say), this choice determines whose invoices you'll see after logging in.
Step 3. Pick "Profil Zaufany" as your authentication method
On the method-selection screen, choose Profil Zaufany. You'll be redirected to login.gov.pl — the government identity hub used by most Polish public e-services.
Step 4. Confirm your identity — via your bank or PZ credentials
Two paths, identical to logging in to the Polish e-Tax Office:
Through your bank: click your bank's logo (PKO BP, mBank, ING, Santander, Pekao, etc.), log in to online banking, and approve the operation the same way you'd approve a transfer.
With PZ login and password: enter your Profil Zaufany credentials and confirm via SMS or app.
Step 5. Sign the authentication request
KSeF then asks you to sign an "authentication request." It sounds bureaucratic; in practice it's one click on "Sign" plus a confirmation in your banking app or by SMS — the digital equivalent of a signature, no paper involved.
Step 6. You're in
After successful authentication, you land back in KSeF. The NIP you're acting under appears in the top-right corner; the left-hand menu holds invoice lists, issuing, permissions, and settings. On your first login, verify immediately that the NIP shown is the right one — that's the most common slip.
Mini-case: A UK-owned design studio with a Polish subsidiary had its Polish director (who holds a PESEL and Profil Zaufany) complete the first login in about five minutes: open ap.ksef.mf.gov.pl, enter the company NIP, authenticate via ING on login.gov.pl, click "Sign" — and the purchase invoices already issued by Polish suppliers were waiting in the inbox.
Common problems and quick fixes
"No permissions for this context." You're logging in to a company NIP without granted rights. For companies, someone must first register you via the ZAW-FA form or grant you permissions inside the system. Sole traders don't face this — owner rights are automatic.
Redirect loops or a blank screen. Usually the browser: clear the cache, allow third-party cookies, or retry in Chrome/Firefox incognito mode.
The bank won't confirm the operation. Make sure you're logging in through the same bank you used to create your Profil Zaufany — confirmation only works in your "home" institution.
System downtime. It happens. Check the status announcements at ksef.podatki.gov.pl before debugging on your end.
Important: manual login ≠ daily workflow
Profil Zaufany is perfect for the first login, browsing invoices, or granting access to your accountant. But you won't log in by hand every time you invoice a client. Invoicing software connects to KSeF in the background using a token (valid until the end of 2026) or a KSeF certificate — both of which you generate after logging in with Profil Zaufany.
Think of the first Profil Zaufany login as the gateway: once through it, you configure access for your software, and KSeF stops needing your attention.
Checklist: your first KSeF login in 6 steps
Confirm your Profil Zaufany is active (pz.gov.pl).
Open ap.ksef.mf.gov.pl/web/ (verify the
mf.gov.pldomain).Enter your company's NIP as the context.
Choose Profil Zaufany → confirm identity via your bank or PZ credentials.
Click "Sign" on the authentication request.
Once inside, verify the NIP in the top-right corner, then generate a certificate or token for your invoicing software.
Wrapping up
A KSeF login via Profil Zaufany boils down to three correct choices: the right address, the right NIP, the right confirmation method. For a sole trader it takes minutes and requires no paperwork.
What follows — issuing, receiving, and tracking invoice statuses — is the part worth automating. Biurko connects to KSeF for you: log in once, and invoices flow to the system and return with their official confirmations (UPO) automatically. Try it free for 14 days at biurko.io.
FAQ
Can I log in to KSeF without Profil Zaufany?
Yes. Alternatives include a qualified electronic signature, a qualified seal (for companies), a KSeF certificate, and integration tokens for accounting software. Profil Zaufany is simply the free, no-software option for individuals — including JDG owners — which makes it the most common first-login method.
Do foreigners need a PESEL number to log in to KSeF?
Profil Zaufany requires a PESEL, so foreign directors without one typically authenticate with a qualified electronic signature instead, or the company designates an authorized person via the ZAW-FA form filed with the tax office. Many foreign-owned companies grant access to their Polish accounting office this way.
Do sole traders need to file anything before the first KSeF login?
No. KSeF automatically grants owner rights to a JDG owner by matching their PESEL with the business NIP. The ZAW-FA form mainly concerns companies without a qualified seal, which must designate an authorized individual to the tax office before first access.
Why does KSeF say I have no permissions?
You're most likely entering the NIP of an entity that hasn't granted you access — for instance, a company that hasn't filed ZAW-FA for you. Double-check the NIP; if it's a company, confirm that permissions were granted and confirmed before retrying.
Do I have to log in to KSeF every time I issue an invoice?
No. Manual Profil Zaufany login is mainly for initial setup and browsing. Day-to-day, invoicing software connects to KSeF automatically via a token (valid until the end of 2026) or a KSeF certificate, sending and receiving invoices in the background.