It appears that lots of 'Pseudo Authority' websites are promoting the idea that dialling 112 rather than 999 is preferable in the UK from a mobile.
It's all utter nonsense.
Dialling 112 in the UK causes the call to be redirected to 999.
There is NO other difference.
Mobiles will use any available signal in an emergency whether you dial 112 / 999.
The only advantage to 112 is its a Pan - European emergency number.
If you're not sure which country your wood is in, then perhaps 112 may be better.
Here's a copied answer from another forum:
It's nonsense, I'm afraid. 112 is in fact re-directed to the same Operator Assistance Centres (OACs) as 999, and the Enhanced Information Service for Emergency Calls (EISEC) or its Cable and Wireless equivalent (ALSEC) works exactly the same. For mobile phones in this country, GPS from the phone is never used for positioning, just the cell(s) the phone is registered with. The data is provided by the mobile phone company to the EISEC or ALSEC service, from where the emergency service you call (providing they have a suitable interface - Police and Ambulance almost all do, Fire much less so), retrieve the data and their Call taking system then plots it on a map. The information is delivered as an ellipse (sometimes this is a circle) of varying size, but out in rural areas sometimes 5 miles across, with a confidence factor in percent, as to how likely the phone is to be actually within the plotted area.
You can find web sites that tell you otherwise, but none are official.
Do you not think that the ambulance / police would promote 112 if all this nonsense were true.
They recommend 999.
Rant over, I hate Pseudo Authority......