Activate an American Express Serve card by purchasing a Serve card online or at a local retailer and registering the card on the Serve website. Current Serve card customers can call 1-800-954-0559 for assistance as of 2015.Continue Reading
To activate an American Express Serve card:
Purchase a temporary card at a local retailer, if desired.
Register the temporary card on the Serve website, or register for an account and request a Personalized card.
Once the personalized card arrives in the mail, log in to the online account and activate the card. Users will then be able to transfer money from their temporary card to their personalized card.