I think it is legit, but it is annoying.If you call the # on your card (not the 800-5234) AmEx will know that 800-5234 called you. They want you to get on a conference call with your bank to confirm your identity. They have not told me what they want to ask the bank. I asked and was told 'some questions' repeatedly. Unfortunately, AmEx's rep had difficulties operating his phone and could not conference in the bank. I was told to call AmEx back; perhaps they'd then be able to conference in the bank. Perhaps the inability to operate a conference call adds to the cocerns that 800-5234 is a scam.There are apparently other ways to verify, but the rep did not want to discuss those and hinted that if I didn't get on a call with him and my bank, AmEx might not be able to verify me. Perhaps this adds to the concerns that 800-5234 is a scam. I imagine this is some kind of advanced security set up, but it is annoying. I've spent more than 10 minutes on this and have not satisfied AmEx's demands. I feel like I've been flagged as some kind of wrong-doer. The rep was vague and evasive; again I understand why some believe that this is a scam, especially if they just call the 800-5234 number. Nice way to start a relationship with a customer.