past_due subscriptions and automatic retry payments in Stripe resulted in multiple subscriptions for a user

[mpvosseller]

We discovered a flow in our app that allowed a user to have two paid / active Stripe subscriptions at the same time (which our app wants to prevent):

• user buys a monthly subscription
• at some point a renewal charge fails because the credit card is expired
• the subscription status is set to past_due
• the user is now no longer considered "subscribed" because on_trial_or_subscribed? returns false
• a few days later the user notices they are unsubscribed and purchase another subscription. We currently allow a user to buy a subscription if on_trial_or_subscribed? returns false). The user enters a new credit card.
• the next day Stripe re-tries a charge for the original past_due subscription (Stripe's default settings are to retry charges for 15 days). The charge works because the user has a new working credit card on file.
• The user now has two active paid subscriptions.

The most obvious solution is to prevent the user from buying a new subscription if they are already subscribed (user.payment_processor.on_trial_or_subscribed?) OR if they have one that is in the past_due status (user.payment_processor.subscription.past_due?)

Wondering if this matches what folks are currently doing or if anyone handles this another way.

Is it worth adding a note about this case in the documentation on on_trial_or_subscribed??

Happy to do that although I'm not sure how this works with other processors.

[excid3]

The joy of payments is in all these little edge cases!

I would consider them not subscribed when they're past due and display a banner that they need to update their payment method to continue using the service. Once it's cancelled or unpaid on Stripe, then you can consider them fully inactive.

[mpvosseller]

Thanks for confirming @excid3. That matches what I was thinking.