Official SIM Unlock - Do not use this service, as the cost for unlocking handset is not clearly specified on their website when making the purchase. Like many others here who have used the service, I was scammed because I didn't read the small print when purchasing the unlock service. I paid £23.99 to have my iPhone 7, which is locked to O2, to be unlocked for use with other carriers. One would assume, that this already extortionate price for handset unlock would be sufficient for the service (as O2 can unlock their handset free of charge, I subsequently found out). However, I was sent an additional email with invoice of a further £52.79 payment to complete the unlock service, which is almost than double the amount of initial cost. I emailed their customer service requesting a refund, to which I received a curt email stating that a refund for the initial payment of £23.99 was not possible, as I had ticked a checkbox upon checkout which stipulated in small print that further costs would be due. Very dubious business model, at best. Especially, when competing services will carry out a full unlock for £20. Utterly despicable sales practice. Please avoid, to prevent a similar experience.