hi, hoping to find a geographical number for this company as i will be making numerous calls to them to try to sort out the rent on my son's student accomodation.
their number and address are:
0870 1997771
27 old gloucester street, london, w1cn 3xx

thanks in anticipation

A Google search shows an awful lot of other organisations using that address (n.b. should be WC1N, not W1CN), so I suspect it may just be a mailbox address.
It may be necessary for you to start by finding a geographical address for the business in order to stand a chance of finding a geographical phone number!
Also, is Fairfax Property the full and exact name of the business?  There does not appear to be a company called Fairfax Property Limited, so do you know if Fairfax Property is the trading name of another company, or is it a partnership or what?

letterhead says just Fairfax Property, does not have plc or ltd after it.
only other info i have is a fax number 07005803538 and the owner Dean Weinberg
BTW looks like his letterhead is wrong because it deff says W1CN !!

Sounds like it's just his trading name; quite possibly the telephone service is not even in the name of Fairfax Properties.  No clues in the rental agreement I suppose?  
Otherwise, there is really little or nothing to go on to help in finding a geographical number I'm afraid.

thanks for trying, i'll get my son to look through the rental aggreement again