Originally Posted by
redvelvetmartinis
I also had this happen to me several times, and I was using/testing a Singapore-issued credit card, and SQ's own co-branded Amex. Hilarious when the system told me Amex was not supported!
That is crappy and should not be happening. Singapore issued Amex cards support Amex Safe Key and should definitely work. Last time I used one has been years ago though as these days I use other cards.