When someone starts a recurring subscription, i pass on the custom
variable which contains the User ID of the user on my system. After the payment I receive two IPNs, subscr_signup and subscr_payment. Both have the custom variable in them which lets me identify the user.
However, for future recurring payments, will the IPN continue to pass on the custom variable? Should I rely on the subscr_id instead of custom?
Thanks.
I found the answer from this page. Yes, the custom variable will always be passed as-is in every consecutive IPN post.
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