Mobile to mobile is complicated on some you can use your "free" mintues if you have a contract depending on the type of number being dialed and the contract you have.
Worth sitting down and looking up your mobiles charges and how they would beast work with the numbers avaiable.
For example i used to use alpha telecome not the cheapest but they had a normal number in fact london 0207 but most mobiles just care if it a normal landline number or not and not concerend with the location code.
I could use my Free mintues with this number so no nasty surpirses.
Also be careful a new cheap call number migt look like a mobile number ie 077 but some phone companes allow in free mintues others dont and it can vary from contract to contract possibly and at any time it might change as you well know.
