Telephone interview: competency based questions. Basic competencies can be found from their website. I was asked, why you want to join us, tell me a time when you are challenged, how to deal with angry customers, etc. The lady was not from TfL. They are sub contracting the work to some HR company. She was really nice but like a robot. The process is not interactive. My first telephone interview+non-native English speaker, so did not end up well. BUT do prepare beforehand, it is really helpful to have 'scripts' in front of you.