I'm interested in Three's range of monthly rolling contracts. Currently I'm torn between the £10 deal (SIM10) with 100 minutes and the £15 deal (SIM15) with 300 minutes. Obviously the latter is much better value for money but I probably dont use much over 100 if any anyway. http://threestore.three.co.uk/simonly.aspx
My question is can I change my tarrif freely (every month) whenever I want so that if I'm going on holiday say or in the run upto Xmas I can switch to the £15 tariff for a month or two and then switch back, or will I have to get a new SIM, port my number etc...