When in the mitel server, Select what unit you will need 


Unit 288 - Main Office 

Unit 20 (Also Unit 21 and Unit 31)

M&M (M&M Office) 

Lockerbie (Forestsawmills) 


IN Devices , Phones. There will all the phones in the system for that office. 


Firstly when setting a phone up try and find a extension number that is free. This will be named "Spare" or something simular 

If there is a spare phone, Change the name and config the phone. 


If there isnt a spare extension number. Right click and create 52x/53x (Does not matter if there is a x or x's in the number as they will disapear) And select a extension number close the what the phones have etc,  If the office have extension numbers 4000-4999 try and keep it in the 4000's 


Select the extension number and create. 


There will be a empty phone number for this now. 


Change the name and config the phone.