Why losing Profil Zaufany blocks invoicing in KSeF
Profil Zaufany (PZ) is a free electronic identity means used to confirm your identity to Polish public administration. In KSeF it is one of the authentication methods for individuals, including sole proprietors (authentication methods, ksef.podatki.gov.pl).
Since 1 April 2026, logging in to KSeF with Profil Zaufany runs through the Węzeł krajowy (login.gov.pl). It is the same profile, now wired into the government single sign-on alongside the mObywatel app, online banking, and the e-Dowód (Poland's electronic ID card). If PZ stops working, you lose your simplest way into the system.
There is a second dependency that is easy to miss. To generate a KSeF certificate, which is the long-term authentication method, you first have to log in to KSeF using Profil Zaufany, a qualified signature, or a qualified seal (KSeF certificates, ksef.podatki.gov.pl). A token alone won't do it. A one-person business that rests everything on a single Profil Zaufany therefore has a single point of failure.
A note for foreign-owned companies: a Polish limited company (sp. z o.o.) usually authenticates with a qualified electronic seal or a KSeF certificate rather than a personal Profil Zaufany. The lesson below still applies, only the primary credential differs.
The most common ways access is lost
Before you try to recover access, find out what actually happened. The fix depends on it.
The profile expired. A Profil Zaufany is valid for 3 years from confirmation and can be extended for another 3 (gov.pl). Once it lapses, it stops working and can no longer be extended; you have to create a new one.
Forgotten password or username. The most common case, and the easiest to fix.
Temporary lock. Several failed login attempts can lock the profile for security reasons.
Bank data mismatch. If you created PZ through online banking and later changed your ID document or surname, the bank's records may no longer match, and the online process won't complete.
A real example: an entrepreneur set up Profil Zaufany through a bank three years ago, later replaced an ID card, but the document number held by the bank stayed old. The profile expired in April. A new one can't be confirmed online because the data doesn't match, so an in-person confirmation point is the only route. Better to know that in advance, not on the day an invoice is due.
How to recover access, step by step
Start by signing in at pz.gov.pl and checking the profile status.
Forgot your username. On the login page choose "Nie pamiętam nazwy użytkownika," enter the e-mail linked to the profile, and receive a reminder in your inbox.
Forgot your password. Choose "Nie pamiętam hasła," enter your username and PESEL (Polish personal ID number). You get an e-mail link and confirm the change with an SMS code. The new password can't match the old one.
The profile is active but near expiry. Open "Szczegóły profilu" (Profile details), choose "Przedłuż ważność" (Extend validity), and confirm your data with e-mail and SMS codes. Validity extends by 3 years.
The profile expired. Sign in to your account (username and password still work), choose "Załóż nowy profil zaufany" (Create a new Trusted Profile), and confirm it via bank, e-Dowód, qualified signature, or a confirmation point.
The profile is locked. Wait, or contact Profil Zaufany support: +48 42 253 54 50 (Mon–Fri 7:00–18:00).
One detail worth watching: after you renew or recreate a bank-created profile, the link to online banking can break and may need to be set up again. Once you are done, log in to KSeF and check that authentication passes before you issue the first invoice.
The KSeF certificate: a backup that doesn't depend on one login
The best time to sort out access is while everything works, not during an outage. The key move is to generate a KSeF certificate while your Profil Zaufany is still valid.
A KSeF certificate is a free cryptographic tool issued by the Ministry of Finance Certification Centre, valid for up to 2 years (ksef.podatki.gov.pl). It works as an authentication means tied to a NIP (tax ID) or PESEL and lets you log in to KSeF without reaching for Profil Zaufany every time. It is also the only method that keeps invoicing running in offline mode.
The logic is simple: with the certificate downloaded and loaded into your invoicing software, an expired Profil Zaufany no longer stops invoicing. You renew the profile at your own pace while the business keeps issuing documents. Just remember the certificate itself has to be obtained first by logging in with a primary method, so don't leave it for the moment PZ has already failed.
How Biurko protects your invoicing
In Biurko you connect to KSeF one of two ways: through Profil Zaufany or through a KSeF certificate. This is about resilience, not aesthetics. If your PZ expires or locks, you switch the connection to the certificate and keep issuing, with no downtime.
Biurko also watches the deadlines for you. Thirty days before a certificate expires, you get a notice to renew it in good time rather than discovering the problem on the day of an outage. Authorization runs in the background, so you are not logging in by hand for every invoice.
Honestly about the limits: Biurko won't recover your Profil Zaufany for you, because that process lives on gov.pl. It also can't generate a certificate if you never had anything to authenticate with in KSeF. Biurko solves a different, more everyday problem: it makes sure one expired login doesn't take down all of your invoicing.
Checklist: secure your KSeF access
Check on pz.gov.pl when your Profil Zaufany expires and put the date in your calendar with a 30-day reminder.
Update the e-mail and phone number on your PZ account so password recovery works.
If you created PZ through a bank, make sure the bank's data (ID document, surname) is current.
Generate a KSeF certificate while Profil Zaufany still works, and back up the files in a safe place.
Load the certificate into your invoicing software as a second KSeF connection method.
After any login change, issue a test invoice and confirm it goes through.
Conclusion
Losing Profil Zaufany is rarely a disaster on its own. It becomes one only when it is your single way into KSeF and a client's payment deadline won't wait. Recovering access usually takes minutes, while an expired profile means creating a new one. The best insurance is a KSeF certificate set up ahead of time.
In Biurko you connect to KSeF with Profil Zaufany or a certificate and switch between them when you need to. Create an account at biurko.io and set the certificate as your backup entry before you ever need it.
FAQ
My Profil Zaufany expired, can I extend it? No. An expired profile can't be extended. Your account on pz.gov.pl still exists, so sign in with your username and password and choose "Create a new Trusted Profile." You confirm it via bank, e-Dowód, qualified signature, or a confirmation point.
Can I issue a KSeF invoice without Profil Zaufany? Yes, if you have another authentication method: a qualified signature or a KSeF certificate loaded into your invoicing software. A KSeF certificate lets you log in and issue documents regardless of your Profil Zaufany status.
How much does recovering Profil Zaufany cost? Nothing. Both extending validity and creating a new profile are free. The KSeF certificate issued by the Ministry of Finance is also free of charge.
How long is a KSeF certificate valid? Up to 2 years, counted from the date given in the application or from the issue date. You can request a new certificate at the earliest one month before the current one expires.
I'm a foreign company operating in Poland, does this affect me? If you run a Polish limited company, you likely authenticate with a qualified seal or a KSeF certificate rather than a personal Profil Zaufany. The backup logic is the same: keep a KSeF certificate ready so a single lost credential doesn't stop invoicing.