Like other credit cards, American Express cards have a closing date, when the billing cycle ends, and a statement due date, when the minimum payment for that billing cycle is due. American Express sets your closing date about 30 days from when you open your account, and each subsequent closing date about 30 days from the last closing date. You can't usually change your close date, but American Express may allow you to change your due date.
Over the Phone
Call American Express customer service using the number on the back of your card. You can also call the general customer service line at 1-800-297-3276.
In the Mail
You can send a written letter to American Express at P.O.Box 981540, El Paso, TX 79998-1540.
After logging into your American Express online credit card account, click on the question mark help button at the top of the page. From there, you can access the online chat feature to speak to a customer service representative about changing your due date.