@martik777
Maybe sign up for the promo before the last day. You could wait a few weeks before signing up so you don't pay for service before you're ready to use it, but the end cost would be more than the buy-one-month-get-two-months promo offer which expires soon.
Public Mobile SIM cards will work in any phone which is not carrier-locked. You can test whether a phone is locked by trying out an active SIM card from any carrier other than the one the phone came from. You can probably borrow a SIM card from a phone belonging to friend or family, you only need it for a couple minutes (long enough to restart, dial in or out, text in or out).
The phone needs to be SIM-compatible, of course. PM SIM cards are supplied in all three standard form factor sizes. PM does not support eSIMs - but this isn't a problem unless you intend to buy an eSIM-only device elsewhere.
Your phone also needs to be radio-compatible. This is basically a non-issue because all Canadian carriers use more or less all the same basic bands and frequencies for more or less all the same things. It's only a problem with really old phones or with new phones intended for foreign regions.
You'll need Public Mobile's APN settings to access data and MMS. Most new phones will autoconfigure, some will require manual configuration, a few will require quirky tweaks to make things work properly. At worst it's a one-time setup which will take a few minutes.
Some older phones won't autoconfigure voicemail. But it's easy enough to manually enter the number as a contact if you must.
