Please read the following instructions before moving on to the Account Manager.
A link appears on the left navigation bar called Manage Card.
Clicking on this link brings you to a new page to manager your cards.
You can Attach Another Card, Combine Accounts and Switch Accounts.
Attach Another Card lets you attach a card to your current username and password.
Combine Accounts lets you combine the wallet balances of multiple cards in to a single, "shared balance" account.
Switch Accounts lets you switch which account is being displayed on the balance and transaction history pages.
To Attach Another Card, click on the Attach Another Card link in the menu.
You must enter the card number and registration code to perform this task. If these are valid and the card is activated, the attachment is done.
You may then go to the Manage Card screen and can see that you have multiple cards on your account.
Then you may click on Combine Account and accounts will be combined for a "shared value" wallet.
Enjoy!