Just received a unlocked m8. I'm in the UK and in the GPS settings there's e911 on and stated it cannot be turned off on any mobile cellular phone.
I'm on the UK so 911 isn't relevant here! Can I get rid of it?
I would think that feature would only be available (or at least locked) on phones destined for the U.S. due to our laws. If you bought it online, that could explain it, because you could have got a U.S. based phone. There's no way to disable it if you're stock. I'm not even sure if it's possible on a rooted phone. I can say from experience that it won't really effect anything for you. I believe it only works in the background if placing a 911 call to make sure you're routed to the right emergency call center.
If it was shipped from America, that would make perfect sense. You may want to contact HTC or a local carrier and see if there's anything they can do to help you if you really want it off, but I personally wouldn't be concerned with it. Chances are, it would require flashing a new ROM that is local to you, be it through official channels like them, or rooting and doing it yourself. I'm not too familiar with that aspect of modifying.