Ok I see. Phones can be locked to a certain provider over here too, but practically *every* phone is possible to buy without it being locked to a specific provider. It usually costs a bit more though, becuase the service providers like to subsidize the phones when they're locked to them.
I think the only exception to this is the iPhone, which caused a shitstorm when it was released

. That phone is now available from two service providers though, but cannot be bought unlocked.
Personally, I always get unlocked phones because I'll save money on it in the long run, because I can use my already existing contract which is much cheaper than anything else for my usage pattern.