Adding seats in Stripe produced a refund instead of a charge
A coupon on a back-dated Stripe subscription can make a seat increase come out negative, so expanding customers get paid instead of billed.
Working notes
One billing failure at a time.
Write-ups of things that go wrong in Stripe and return success while doing it. Each one covers the symptom, what Stripe is actually doing, where to look to confirm it, and how to put the money back.
Metered usage that never reached the Stripe invoice
Usage-based invoices come out short when meter events go unattributed. The failure points between your event and the invoice line, and how to reconcile them.
One Stripe customer with several open invoices at the same time
Open Stripe invoices stack on a single customer while each one stays individually valid. Where the extras come from and how to clear them without losing the real one.
Stripe amounts are a hundred times off in JPY and other zero-decimal currencies
Stripe takes amounts in the currency's minor unit, so a hardcoded multiply by 100 breaks JPY, KRW and the currencies Stripe special-cases. How to find and repair it.
Stripe coupon attached to the subscription, no discount on the invoice
A Stripe coupon can be attached, valid and unexpired while discounting nothing, because its applies_to product list matches no line on the invoice.
Stripe says they downgraded and the app still grants the old plan
The subscription in Stripe and the access your own code grants are two separate records, and nothing reconciles them. What drifts, how to check it yourself, and why Murphy does not cover this one.
The payment failed, the invoice is open, and Stripe never retried
When Stripe dunning stops, next_payment_attempt is null and no event announces it. The reasons a retry never happens, and how to find the invoices it left behind.
Stop reading and go look.
Murphy checks for the ones in this list against your own Stripe account, and the first report covers the invoices you already have.