Did you just find a file that has been digitally signed by British Telecommunications Plc? If so, please read on.
You'll typically see British Telecommunications Plc when double-clicking to run the file. The publisher name shows up as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can also view the British Telecommunications Plc certificate with the following procedure:
Here's a screenshot of a file that has been digitally signed by British Telecommunications Plc:

As you can see in the screenshot above, Windows states that "This digital signature is OK". This implies that the file has been published by British Telecommunications Plc and that no one has tampered with the file.
If you click the View Certificate button shown in the screengrab above, you can view all the details of the certificate, such as when it was issued, who issued the certificate, how long it is valid, etc. You can also view the address for British Telecommunications Plc, such as the street name, city and country.
VeriSign Class 3 Code Signing 2004 CA, VeriSign Class 3 Code Signing 2010 CA and VeriSign Class 3 Code Signing 2009-2 CA has issued the British Telecommunications Plc certificates. You can also see the details of the issuer by clicking the View Certificate button shown in the screenshot above.
These are the British Telecommunications Plc files I have gathered, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 0/43 | btwsp50.sys |
| 0/48 | pcControlHost.exe |
| 0/47 | BTHelpNotifier.exe |
| 0/50 | PTICA5F.tmp |
| 0/47 | McciControlHost.exe |
| 0/51 | FlDesktopHelpInstall.exe |
| 0/45 | Setup.exe |
The detection percentage is based on the fact that I've collected 331 scan results for the British Telecommunications Plc files. 0 of these scan reports came up with some sort of detection. If you like, you can review the full details of the scan reports by examining the files listed above.
The analysis is done on certificates with the following serial numbers: