Received an email from AMEX: if you add an Additional Card Member (Authorized User) to a Platinum card and that card spends $2,000 in six months, you can earn 20,000 Membership Rewards points. Here are the links—check whether you can activate it, and if it works, go for it. Green also has a 5,000 MR bonus.

From prior experience, the best option for Platinum is to add a Gold AU (yes, a Platinum cardholder can add a Gold AU). The reason is that Platinum AUs have an annual fee, while Gold has no annual fee (up to four cards). The offer does not require you to add a Platinum AU, and a Green AU is simply Green, with no annual fee, so no worries there.

If your Additional Card Member has a separate address, you can enter it. This is pretty handy—other banks usually default supplemental cards to the primary cardholder’s address. If the address is the same, just check the same address option.

After a bit of waiting.

By the delivery speed, it looks like regular mail. Not sure if the Platinum AU can be delivered by UPS Express/Next Day.

Here are the offer terms. They still don’t mention whether points could be reclaimed if the card is closed within a year, so keep that in mind. For safety, it’s best not to use gift cards to complete the qualifying spend.

OFFER TERMS
Add one or more new Additional Card Members to your account and you can earn 20,000 Membership Rewards points for the first Additional Card Member that spends $2,000 or more in eligible purchases on their Card within their first 6 months of Card Membership starting from the date on which the Additional Card Member is added. The maximum you can earn as part of this offer is 20,000 Membership Rewards points. Purchases made by other Additional Card Members on your Account will not count toward the $2,000 purchase requirement. Purchases made by eligible Additional Card Members will not be combined to satisfy the $2,000 purchase requirement. Your purchases as the Basic Card Member will not count toward the $2,000 purchase requirement.

You can earn 20,000 Membership Rewards points after the Additional Card Member spends $2,000 or more on eligible purchases on their Card within their first 6 months of Card Membership starting from the date on which the Additional Card Member is added. In rare instances, the Additional Card Member's period to $2,000 may be shorter than 6 months if there is a delay in receiving their Card. Also, purchases may fall outside of the 6 month period in some cases, such as a delay in merchants submitting transactions to us or if the purchase date differs from the date they made the transaction. (For example, if they buy goods online, the purchase date may be the date the goods are shipped) . The 20,000 Membership Rewards® points will be applied 8-12 weeks after the Threshold Amount is met.

If we in our sole discretion determine that you or your Additional Card Members have engaged in abuse, misuse, or gaming in connection with this offer in any way or intend to do so (for example, if you added one or more Additional Cards to obtain an offer (s) that we did not intend for you; or if you or your Additional Card Members cancel or return purchases made to meet the Threshold Amount), we may not credit Membership Rewards points to, we may freeze Membership Rewards point credited to, or we may take away Membership Rewards points from your account. We may also cancel this Card account and other Card accounts you and your Additional Card Members may have with us.

Your account must not be canceled or past due at the time of fulfillment of any offers.
Eligible purchases are purchases for goods and services minus returns and other credits. Eligible purchases do NOT include fees or interest charges, purchases of travelers checks, purchases or reloading of prepaid cards, purchases of gift cards; person-to-person payments; or purchases of other cash equivalents. Additional terms and limitations apply.

The annual fee for the Platinum Card is $695. The annual fee for Additional Cards is $175 for up to 3 Additional Cards. The annual fee for the 4th or more Additional Cards is $175 for each Card.

There is no additional fee for Gold Cards.

American Express reserves the right to modify or revoke offer at any time.

Terms and Conditions for the Membership Rewards® program apply. Visit membershiprewards.com/terms for more information. Participating partners and available rewards are subject to change without notice.

The value of Membership Rewards points varies according to how you choose to use them. To learn more, go to www.membershiprewards.com/pointsinfo.