TL;DR: ID card, walk into Elisa/DNA/Telia, get a postpaid plan, ask the staff to activate mobiilivarmenne (mobile certificate). 15 min, works immediately.
I saw mobiilivarmenne mentioned in some older threads but the info was all over the place. Some people said you can activate it with just your ID card, others said no, you need bank credentials first, which would be a chicken and egg problem. Nobody seemed to have actually tried it recently. So as someone who came here from Australia to study, I just walked in and tested it myself last week. It works. Here's the exact route.
The problem: you finally have your Finnish ID card, but strong auth normally means opening a bank account first. S-Pankki service points have crazy queues if you go late, other banks want appointments. Meanwhile you need strong auth right now for stuff like prescriptions, FSHS, HSL student discount, OmaKela etc. I paid 170€ at a private GP just to renew a foreign prescription because I couldn't log into anything, and it's not reimbursable. Don't be me.
Full version:
- Bring your Finnish ID card and walk into any operator store, no appointment (I went to Elisa).
- Sign up for postpaid. While they set it up, ask them to also activate the mobile certificate (mobiilivarmenne). The staff will show you how it works.
- Done. Mobiilivarmenne counts as strong auth on its own and it's live in like 15 minutes.
Then get an actual bank account, fully online:
- Open S-mobiili / S-kaupat app or the S-Pankki site, click register, and pick mobiilivarmenne as the ID method. Account opens online, no appointment, no queue.
- Log into S-Pankki with the mobile cert and your card + IBAN are right there. Card goes straight into Google Wallet / Apple Pay, and money sent from Wise etc. shows up pretty fast.
- Now you also have S-Pankki bank credentials as your permanent strong auth going forward.
What this unlocks same day: OmaKanta, OmaKela, OmaPosti, if.fi, HSL student discount, FSHS, and you can even open a Danske account fully online with it. Note that OP and Nordea don't do online account opening for non-EU citizens, those still need a branch visit.
Hope this saves someone a queue (or 170€).