Under certain circumstances Amex will issue a Corporate Account to companies with the exposure limit backed by a deposit or bank guaranty. The company must meet certain requirements such as annual revenue/sales of at least $4 million. The deposit will be on "hold" while the accounts are secured. They will review the account annually to see if they can release the deposit or bank guaranty.

I have a friend who works as a Relationship Manager for a local bank. He was able to arrange for a premium credit card to be issued, by their Bankcard Center, for one of his clients. The client would not have been approved through the regular route. His department assumed liability for the credit line and the department held funds as collateral. The credit card is considered unsecured because the bankcard center has no way of knowing that the department is holding funds as collateral.