You usually can't take advantage of promotional bonus points offers and other introductory offers if you're an existing American Express cardholder. If you've held an Amex credit card in the past, you may have to wait around 18 months until you can qualify for another bonus points offer that's only eligible for new cardholders. If you're unsure, check the terms and conditions or contact American Express directly to confirm if you're eligible to earn the bonus points.