CiviCRM Community Forums (archive)

I have not found a good description on how Civi handles membership renewals with payments.  My assumptions are as follows (please correct any and all mistakes that I make):

• Member signs up using a contribution form and selects 'please renew my membership automatically'.  The membership costs $10
• Member submits form.  The payment request is sent to Paypal (or other processor) for verification
• Paypal processes the payment and returns some type of code confirming the payment.  If no confirmation is received, the contribution remains in pending mode and has to be manually updated.
• Eventually the contribution succeeds and the membership becomes active.

This is the part that I am very fuzzy on:

• When the membership expires, one of the cron jobs checks to see if the membership had a renewal request.
• If yes then Civi attempts to charge for the membership at its current rate to the payment processor.
• I am not sure where the credit card information is stored, therefore my assumption is that the payment processor must have it and the requested payment is processed using the saved credit card credentials
• As before, if paypal is successful then some code is returned and a new contribution is reported to Civi and their membership is extended.
• If the payment is unsuccessful (expired card or similar), then paypal returns some error code and the contribution is reported as failed or pending and the membership expires

Are my assumptions above correct?  My largest assumption is that the payment processor stores the credit card credentials at the request of CiviCRM upon the initial transaction?  If not, how is an automatic renewal performed? 

I have read many blogs and documents describing what a renewal can offer a member, but nothing describes the actual cron job or process that makes this actually happen or what the results of a failed renewal are.

Thanks