The article TsVk! linked to is somewhat out-of-date. Just the other day, OFCOM - the UK telecoms 'watchdog' - announced that from the beginning of 2021, it will henceforth be illegal for providers to 'lock' handsets to the network.
It's a long-overdue move that will be welcomed by many, although more and more 'unlocked' handsets have been available on the market over here in recent years. Why should you have to buy another handset, simply because you want to switch providers?
There is a caveat to all this, of course. 'Older' phones, using removable SIMs or microSIMs wouldn't be such a problem. The incoming new standard, however - the "iSIM" - could prove to be more problematic, given that these are soldered to the phone's mobo, and have to be 'reprogrammed' instead.....which can only be done by your provider, so that kinda brings us back to the original issue!
It should be 'do-able' if the phone supports the right frequency bands (as others have said). I wish you luck, but don't be surprised if issues DO crop up.....
Mike. 