I think the people in the op's office may be getting a little confused between UK phones and US ones
IIRC due to an FCC law in the States all cell phones over there have had GPS fitted as standard for the last 5 years or so to allow for them to be tracked when someone dials 911
I think the US law requires cell phone companies to be able to provide the handsets location to within something like 50m, and the easiest way to do that is via a basic GPS system (probably not as capable as normal GPS, but if you can pick up just 2 or 3 GPS satellites* you can get a reasonable lock, if you're also picking up a ground station such as a cell phone tower).
For landlines it's done via reverse directory look up or something similar, basically the emergency services have a list of the physical addresses of all landline numbers (provided by law by the phone companies), so when they get a call it shows the address provided. IIRC some of the phone companies got into trouble when it turned out they weren't supplying accurate/up to date lists.