Certificate Installation — MUP, Pošta, Chamber of Commerce, e-Invoice
Certificates have become part of everyday life — for e-invoices, e-banking, e-Government, the biometric ID card. But when it’s time to install them on a computer, most people hit a wall: the browser blocks it, the reader won’t work, the smart card driver doesn’t respond, Java throws an error. We solve this every day.
Which certificates we install most often
- Pošta CA (Pošta Srbije) — the largest domestic issuer. For e-Invoice SEF, e-Government, some e-banking services
- Halcom CA — financial transactions, e-banking at most banks, e-invoicing
- MUP CA — Cyberveni / qualified electronic certificate on the biometric ID card, use of the e-reader
- Serbian Chamber of Commerce CA — for companies and entrepreneurs, a corporate certificate for business
- Republic of Serbia (CACertSrbije) — the state certification authority, root for many services
- Certificates on eToken / Aladdin USB — driver setup, browser integration
- SEF (Sistem e-faktura) — connecting to the Ministry of Finance for B2G and B2B invoices
Why people usually can’t do it themselves
The browser blocks the certificate
The certificate needs to be placed in the system’s trust store, not just in the browser. Chrome and Edge use Windows’ system certificate store, while Firefox has its own. If the root CA isn’t installed in the right place, the certificate works in one browser but not another. The user thinks it’s their own fault.
The smart card reader isn’t recognized
A typical Gemalto, Aladdin, or SCM Micro reader needs a specific driver — and often the one that comes with the MUP card is NOT compatible with Windows 11. You have to track down a generic PC/SC driver and register it in the system. Several hours wasted.
The Java applet won’t run
Many Serbian portals (especially older banking ones) still use Java applets for signing. Chrome and Edge dropped support back in 2017 — Java simply won’t run. The fix is installing an older Firefox ESR version or the portable Pale Moon browser, plus a specific Java JRE version (usually 8.x).
A certificate on an eToken after a Windows reinstall
The most common reason people call. You reinstall Windows, and the eToken is left as a USB stick that “doesn’t work”. The reason — the middleware that reads the certificate from the token (SafeNet Authentication Client) isn’t installed, or it’s the wrong version. We keep licensed versions on hand and know which one goes with which token.
A conflict between multiple certificates
If you have Halcom for banking and Pošta CA for e-invoicing, the system sometimes picks the wrong one when you log in — which means you sign in as someone else (if you’re using the same server). The fix is to label the certificates properly and set the browser to prompt for your choice every time.
Exactly what we do
- Installing a single certificate with all the required drivers
- Setup in the system certificate store + browser store
- Configuring the smart card reader (if it’s a hardware-based certificate)
- Verifying communication with the portal (e-Invoice, e-Government, e-banking — we test that it works)
- Backing up the PFX file if it’s a software certificate — it doesn’t stay on our computers
- A quick guide on what to do if it “disappears” after some Windows update
For companies with several certificates (say, MUP for the director + 3 Pošta CA for employees), we offer a package with a better per-certificate price.
Service prices — in the official price list
All service prices (diagnostics, repairs, cleaning, reinstallation…) are on our price list page and always up to date. We confirm the final price after a free diagnostic, before any repair. A courier picks up and returns your device, or you can drop it off at one of our locations.
Courier service for businesses and individuals
Need the certificate on both your laptop at home and the PC at the office? Send the device by courier — we pick it up, install it, and return it. All done the same day if you send it before 14h.
Questions we hear a lot
I have Pošta CA on a USB, and after reinstalling Windows it doesn’t work — now what?
It’s most likely the SafeNet Authentication Client that isn’t installed. We have licensed versions for Pošta CA tokens. Bring in the USB and the laptop, and in 30–45 minutes everything works. If you don’t have the original token and need one, we’ll advise you on how to get a new one from Pošta.
I need a certificate for e-invoicing — where do I buy it?
The fastest route — Pošta Srbije (Pošta CA). They have an issuing center in Belgrade, and submitting the request takes about an hour. You pay Pošta for the certificate and it’s issued for 2 years (check the current price with them). Then you bring it to us so we can set it up on your computer and connect you to the SEF portal.
How long does the installation take?
Typically 30–60 minutes per certificate. If the problem runs deeper (a Windows update issue, a Java conflict), it can take up to 2 hours. Usually done the same day when you drop the device off with us in the morning.
Do you guarantee it will keep working after a Windows update?
Absolutely not — Microsoft often breaks certificates with its updates. But if that happens within the first 6 months, we reinstall it for you free of charge. For our regular business clients, we also offer a monthly maintenance plan.
Can you train me to use e-invoicing myself?
Of course. We offer an add-on service — a 1-hour training session with a fully working setup. You’ll learn how to create, read, and export invoices, and what to do if something breaks.
We cover every Belgrade municipality
Our courier picks up and returns devices across the whole city. Click your municipality for the neighbourhoods we cover, the problems we fix most often and arrival times: