Thanks for the excellent question.This is a tricky question, because the answer is slightly different, depending on whether or not you were using ERP ( Enhanced Recurring Payments ) with your PayPal Standard Buttons; or not.
Case #1 ( the normal situation / ERP was NOT being used )If you were using the free version of s2Member with PayPal® Standard integration
( and you were NOT paying for the ERP add-on service at PayPal ), then any existing paid "Subscriptions" to your site, will be tied to the PayPal account of each of your Customers
( that's how Standard integration works ).
The only way for your Customers to cancel their own "Subscription" is by logging into their own PayPal® account and clicking Cancel. You can make this process easier for them, by providing them with a special PayPal Cancellation Button, which can be generated by s2Member, under:
s2Member -> PayPal Buttons -> Cancellation Buttons^ It's important to note that s2Member Pro Forms for Cancellation, will NOT work for existing Customers that signed up using a PayPal "Button". You will need to instruct those Customers to log into their PayPal account and cancel their Subscription, or contact you via email, so you can cancel billing for them.
^ Starting with s2Member Pro v3.5.8+, the Pro Cancellation Form will automatically detect this scenario, and provide the Customer with a link & instructions about how to cancel their "Subscription" via PayPal®. This feature has already been added to the maintenance release of s2Member Pro v3.5.8 ( coming soon ).100% completed, ready for release
Once this is released, one Pro Form can work for both old and new Customers; very simple.
Case #2 ( if you were using PayPal Standard + Enhanced Recurring Payments )All of your Customers are tied to a "Recurring Profile" at PayPal, instead of a "Subscription". So this makes it simpler for your Customers, because they can just use the built-in Cancellation Form that comes with s2Member Pro. This can be generated under:
s2Member -> PayPal Pro Forms -> Cancellation Forms. So in this case, one Pro Form can work for both old and new Customers; very simple.
Case #3 ( all of your Customers were processed through s2Member Pro Forms w/ PayPal Pro )All of your Customers are tied to a "Recurring Profile" at PayPal, instead of a "Subscription". So this makes it simpler for your Customers, because they can just use the built-in Cancellation Form that comes with s2Member Pro. Very simple. This Pro Cancellation Form can be generated under:
s2Member -> PayPal Pro Forms -> Cancellation Forms