When creating and editing a Product, you will have the ability to set certain options that define the behavior for Subscriptions that are created to a Product (via a Subscription signup) and Subscriptions that are migrated to that Product (via an Upgrade or Downgrade, for example).
Return URL and Parameters
In these fields, you may define URLs, optionally with dynamic parameters, to which the Hosted Payment Page would redirect after a successful signup and/or credit card update. The behavior of these fields is covered further in the documentation on Hosted Page Settings. Hosted Page Integation discusses the integration use-cases for these values.
Used to specify a unique identifier for this product that you can use in API calls. If you do not provide an explicit value here, a handle will be generated for you. This can be considered a “friendly” identifier. You could just as easily use the numeric ID to identify the resource.
Credit Card Settings
For each product, you can select the display and validation settings for the presence of a credit card.
Request credit card at signup?
This option affects the Hosted Payment Page, and controls whether or not the credit card fields are displayed within the signup form.
Require credit card at signup?
This option displays whether or not the credit card must be present in order for any signup attempt to be valid. This option affects both the Hosted Payment Page and API. Hence, even if you are using the API for integration, if you want to be able to create a Subscription without an associated credit card, then you will need to uncheck this box.
NOTE: Creating Subscriptions without a credit card will only currently work if there is a zero amount due at signup. Chargify will not create a Subscription with a positive balance, at the time of this writing.
Billing and Shipping Address settings
These setting should be self-explanatory. Like the Credit Card Settings described above, the “Request” option controls the Hosted Payment Page while the “Require” option controls all Subscription creations.