I was recently approved for my first non AU AMEX card. I still haven't received the card yet and I was hoping they backdate to the date of an old AU card I had.
I am prepared to fax them an old statement if they ask for it, but something happened that made me think I might not even have to do it... They emailed me saying thank you for providing an "updated" email address. It seems they still have me and my old email address in their records somewhere. Unless this is a default message that they sent to all new members?!
I think you'll be good. DW apped for Zync in August and she got the card backdated because she is an AU on two of my Amex CCs.