Why do all other cards have Chip and PIN, but American Express doesnt?
Some American Express cards are Chip and PIN enabled, but you should expect to see signature cards alongside Chip and PIN cards for the foreseeable future. Visiting international and UK Cardmembers will continue to present cards without chips, as will some disabled customers. You must still accept non-Chip and PIN cards. If you are presented with a card without a chip, just swipe it, as you would today. The terminal will prompt for a signature. There are some cards in circulation with chips but no PINs once again, the terminal will prompt for a signature for these cards.