I have integrated Shopify subscriptions using the Billing API and am listening for the APP_SUBSCRIPTIONS_UPDATE webhook callback event. However, a failed user billing payment did not trigger the event callback. I now have a further concern: if the user subsequently makes the payment, will that trigger the APP_SUBSCRIPTIONS_UPDATE event callback?
The APP_SUBSCRIPTIONS_UPDATE webhook only fires when the subscription’s status changes (e.g., ACTIVE → FROZEN, CANCELLED, EXPIRED). A single failed payment attempt does not itself change the status, so no webhook is emitted. Shopify will retry the charge over a grace period, and only if all retries fail will the subscription move to FROZEN — at which point you’ll get the callback.