Creating and Accessing Your Personal Account
If you already have an Amazon.com account, an Amazon Payments account has already been created for you that allows you to make payments using credit cards to merchants who accept Amazon Payments. There is no separate registration process. This account will be activated when you make your first payment on any third-party website that accepts Amazon Payments.
To activate a Personal Account, simply make a purchase with any merchant that accepts Amazon Payments. Use your Amazon credentials when you are asked for your user name and password, and then select a credit card from your Amazon.com account to complete the payment. A Personal Account will be automatically activated for you when you confirm payment.
If you want to pay using a bank account, you must verify your Personal Account.