Having a credit score of over 800 out of 1000 and in a position to look at buying my first house, going from the end of a contract with EE that was £36 a month, not missing a single payment, with the phone still in tact, i decided to opt for a sim only deal. O2 offered more data for the money (£8) a month. So i applied…..and was declined. Credit score dropped over 80 points. O2 gave no justification as to why they declined the application. Really bad customer service. I went back with EE in the end for an extra £2 a month. Can not understand their criteria at all and felt totally disregarded by any staff i spoke to. I would recommend staying well clear of o2