Field Name	Type	Description
id*	String	The GUID of the payment method.
isPrimary	Boolean	Default is false. Can only be one primary payment method per payer. Setting one as primary will automatically remove isPrimary status from other payment methods under the payer.
creditCard	Object/Hash	Object containing credit card fields. See the the credit card object for more information. For each payment method, either the creditCard or the eCheck object is required (but never send both).
eCheck	Object/Hash	Object containing eCheck fields. See the the eCheck object for more information. For each payment method, either the creditCard or the eCheck object is required (but never send both).
billingAddress	Object/Hash	Object containing billing address fields. See the billing address object for more information.

{
      "id": "as48fdn4-sdifn448df-84nxxxxxxxx",
      "isPrimary": false,
      "creditCard": {
        "cardholderName": "Jane P. Doe",
        "cardNumber": "4111111111111111",
        "expirationDateMonth": 12,
        "expirationDateYear": 2023,
        "cvv": "123"
      },
      "eCheck": {
        "nameOnAccount": "",
        "routingNumber": "",
        "accountNumber": "",
        "accountType": ""
      },
      "billingAddress": {
        "addressLine1": "string",
        "phoneNumber": "string",
        "city": "string",
        "state": "string",
        "zipCode": "string"
      }
    }