Mobiles UK do not disclose what they are checking. I selected several phones to find out what they would cost but only purchased two, one for each child. What I didn't know was that they would credit check you for everything in your basket ! Be very careful to remove these as it affects your credit score even though they tell it wont. This is possibly a breach of trading standards and when confronted they told me there was nothing I or they could do. I would not recommend these brokers. I would go to a shop and get a face to face service where you know what is going on.