贝宝定期付款-如何防止重复？

Question

So I've been using paypal recurring payments for about a year now, and for the most part it works well (with IPN verification after payment goes through, etc...)

One issue I have run into is sometimes my customers will set up multiple payment profiles, which I definitely don't want them to do. Then I have to go in + refund payments and cancel additional profiles.

I was curious if anyone had any suggestions to prevent users from doing this, or WHERE I should prevent this from occurring.

After the IPN notification hits my server, users can't purchase again, but sometimes this can take 30 seconds, or an hour. So then my user goes back in thinking it didn't go through and purchases again.

My process is pretty much this:

Page 1 (user selects options)
  Paypal API: SetExpressCheckout 
Page 2 (user goes to paypal, logs in, accepts agreement) 
Page 3 (I create the agreement)
  Paypal API: GetExpressCheckoutDetails
  Paypal API: CreateRecurringPaymentsProfile

I would think somewhere on Page 3 I should do a check, but I'm not 100% sure HOW I should go about it. Simply make an association w/PayerID they they tried to purchase something here then prevent it ongoing?

What do people recommend?

Thanks!

Answer 1

After creating the first recurring payment profile, in the response you will get a profile id and a profile status which should be 'ActiveProfile'. I would recommend that you save it, and do a check before he selects any subscription(or product) again on Page 1.