Under a new promo, American Express Platinum and Premier Gold Cardmembers may be able to get 10,000 Membership Rewards points for each additional cardmember they add onto their account. This bonus is good for up to 5 additional authorized users for a maximum bonus of 50,000 Membership Rewards points.

Adding up to 5 authorized users on a Gold Premier card is free, while Platinum cards will be charged a total of $45 for 5 additional users.

In order to get in on this deal, you’ll need to phone Membership Rewards at 1-800-AXP-EARN and mention offer code 5721 (or call the number on the back of your card), but do note that this is a targeted offer, meaning that you may need to try multiple times before finding a CSR that will agree to apply this offer to your account.

Additional cardmembers must be at least 15 years old and you will need to supply their names, date of birth and social security number. You’ll also need to spend at least $1 on the additional card in order to receive the bonus points.

(Via FT)