Sorry, I think I was a little unclear. I also realise that the spending power could be 'account wide' throughout all the supplementary cards under my master account. However, what I wanted to do was to limit or cap one of these supplementary cards to a level way below my (or even a portion of my exposure). My exposure is around £16K ($27K), but I would like one of these supplementary cards to have a spend limit of around £1500. However, after speaking to a CSR at Amex, I was told that no such limits could be applied and that my entire exposure must be afforded to all supplementary cards. Is this also your understanding?