You can downgrade the American Express Platinum card by calling customer service at (800) 528-4800. There is no option to downgrade online or through the mail. When you downgrade American Express Platinum card, be aware that you cannot downgrade from a charge card such as American Express Platinum card to an Amex credit card that allows you to carry a balance without restriction. That means your only options are to downgrade to either the American Express® Gold Card or the American Express® Green Card.
After the downgrade is approved, your existing American Express Platinum card will temporarily have all the features and benefits of the card you downgraded to, so you can use it until the new card arrives, usually in about 7-10 business days. You will be able to keep your card number after you downgrade American Express Platinum card, but the downgraded card will come with a different expiration date and 3-digit security code. If you’ve kept the card open for at least 12 months, any unused rewards will transfer to the new card. Regardless of how long you’ve had the card open, all APRs will stay the same.
You’ll receive a pro-rated refund on your American Express Platinum card annual fee based on the number of months in the year you’ve had the card. You will then be charged a pro-rated annual fee on the downgraded card. You won’t be eligible for an initial bonus for either the Amex Gold card or American Express® Green Card, however.
American Express uses a soft pull for downgrades, so there’s no effect on your credit score.