How it Works

Nothing.

911 is not a recognised code in the UK and no valid telephone numbers begin with those digits. In most cases you will hear "The number you have dialled has not been recognised". 

I'm living in Sweden at the moment and here it's 112, but 999 also connects.

In answer to happy_face's question, it was changed for two reasons I believe.

1) it's harder to sit on your mobile and inadvertently dial the new 112 combination, as opposed to three consecutive numbers 000 (also children are less likely to press the new combination if playing with the phone).

2) on old bell and 'dial' phones, ' 0' was the last hole on the dial so in an emergency you had to wait for it to recoil all the way back round to the start position for each of the '0's dialled.

I've always believed this to be the reason, but will stand corrected if anyone knows differently.

In Germany it's 110 for Police and 112 for Ambulance or Fire Brigade.

However, and strangely, to call for an Ambulance you must first contact a doctor otherwise an ambulance won't be sent out to you!  It's pretty weird!  Fire Brigade are also used as the ambulance service.  It's all very confusing and I'm still confused about it now!! :)

Don't forget 112 is the standard GSM emergency number as well. Even if you can't make any other calls (wrong network, no credit etc.) as long as you are in a coverage area of any network dialling 112 will connect to the emegency services in any GSM network in the world.

Australia uses 000