How you make calls from your College telephone depends on whether the recipient is internal or external.

Types of call

External business call

Dial 9 followed by the full telephone number you require, including the dialling code, to make an external call for business purposes.

Internal call to a recipient at the same campus

Dial the five digit extension number you require to make an internal call to a recipient based at the same Imperial campus as you.

Call a College mobile using Mobex

Dial the five digit Mobex number you require to make a call to a College mobile.

Classes of Service (CoS)

A College telephone will have a Class of Service (CoS) attached to it, which restricts the type of call you can make from that particular device. 

Contact your Telecoms Representative to change the CoS on your telephone.