Without the customer, e-commerce wouldn't be very exciting (or profitable), so a thorough understanding of the customer as treated by FoxyCart is important for any merchant or developer using FoxyCart.

There are two ways to create a customer record in FoxyCart. The first and most common is to allow the customer record to be created automatically upon a successful transaction. The second method is to create the customer record directly via the API.

Regardless the method of creation, the single most important piece of a customer record is the email address used. The email address can be considered the unique key for the customer; there cannot be two different (non-guest) customer records with the same email address.

Depending on the store configuration, FoxyCart can allow customers to checkout as guests or to checkout with an account. Guest customers:

• Do not enter a password.
• Can enter an email address already used by other guest or saved customer records.
• Cannot choose to save their payment information. (This option is hidden from the checkout if in guest mode.)
• Cannot purchase a subscription. (Guest mode as an option is hidden if a subscription is in the cart.)
• Cannot be created or edited via the API (though they can be retrieved).
• Cannot retrieve their information if they purchase again in the future and enter their previously used email. (Because they have no password, there'd be no way for the customer to authenticate anyway.)
• Cannot be converted into a non-guest customer.

Non-guest customers:

• Must have an email address unique among non-guest customers.
• Are required to purchase a subscription.
• Can choose to save their payment information.
• Can be created and edited via the API.
• Can enter their previously used password when returning to a checkout page, or can checkout as a guest (if guest checkout is allowed by the store).
• Cannot be converted into a guest customer.

Non-guest customers can have one and only one saved payment method associated with their account. If a customer has a subscription associated with his or her account, the checkbox to elect to save the payment method on checkout is required to be checked, and an error explaining this is displayed if it is unchecked.

What is important to note is that if a customer has an active subscription being paid for by credit card xxxx1234 and makes another purchase in the future using card xxx5678, that new card becomes the only saved payment method for the customer, and all active subscriptions will use that new card when they run. (While this may sound problematic, in 3+ years we haven't heard of it being an issue. That said, if you have a situation where multiple separate payment methods are required please let us know.)