On a co-branded card, the brand of a company other than American Express will be displayed prominently on the card in addition to the American Express payment network logo and whatever other American Express branding.
A non-exhaustive list of co-branded cards issued by American Express in the United States are the cards it issues in its Delta Air Lines and Hilton Hotels product families.
Credit underwriting standards for American Express issued co-branded credit cards are believed to be less strict than for American Express issued non-cobranded credit cards.
However, you can still certainly be denied for an American Express co-branded product.
I would expect that underwriting for American Express co-branded charge cards to be the same or similar to charge cards that are not co-branded.
For co-branded cards, sign-up bonuses and rewards will usually be in units of the co-brand's loyalty program.
Significant exceptions are the co-branded American Express Platinum charge cards such as the American Express Charles Schwab Platinum charge card and the American Express Morgan Stanley Platinum charge card.
In the United States, for the American Express Platinum charge card, the sign-up bonuses and rewards are in units of Membership Rewards regardless of whether the card has a co-brand.
An American Express issued co-branded credit product can only be product changed to and from the same co-brand and both cards must either be personal cards or both cards must be small business cards.
A customer will not be able to product change a Delta card to a Hilton card.
A customer will not be able to product change a personal Delta card to a small business Delta card.
What happens should the co-branding agreement between the co-brand and American Express terminate will differ case by case.
In the case of the American Express co-branding relationship with Mercedes terminating, what had been the Mercedes-Benz co-branded Platinum charge cards became "vanilla" Platinum charge cards.
"Vanilla" meaning a Platinum charge card without any co-brand.
In other cases, such as when Barclays became the issuer of JetBlue co-branded credit cards, your existing card will be taken over by another financial institution.
In the case of Barclays taking over the JetBlue accounts, future product changes would then be governed by whatever rules Barclays has.
A credit product might be issued by American Express with or without a co-brand, or a card might be issued by another financial institution but the card runs on the American Express payment network.
American Express has also used the term "Platinum" to apply to one its personal Delta co-branded credit cards and one of its small business Delta co-branded credit cards.
Other than having the word "Platinum" in the name, the Platinum charge cards and the Delta co-branded credit cards are different products with different annual fees and different benefits.
If you find that to be inadequately confusing, Delta Airlines also has the Platinum Medallion Status tier in its loyalty program.
Other airlines may also have Platinum tiers in their loyalty programs.
American Express issues several co-branded credit cards.
The annual fees for American Express co-branded credit cards range from zero dollars per year to hundreds of dollars per year.
Depending upon your needs and wants versus what a given product offers, a card with a high annual fee could be either a complete waste of your money or seemingly too good to be true but actually be true.