The billing_cycle_anchor cannot be changed at any point during the subscription's lifecycle. Tilled calculates all future payments from the initial date once the first payment is made. If the billing anchor needs to be changed, we recommend canceling the previous subscription and starting over with the new anchor.
Can I update a subscription’s payment intent directly?
Yes. However, updating the payment intent will not affect the subscription’s status. If the subscription has a status of past_due, users should update the subscription with a valid payment method and attempt to retry it.
Why does a previously declined subscription payment schedule out for a future time to process when it is resubmitted after updating the payment method?
This is because the payment intent is still considered a subscription payment which dictates its behavior to resume processing at the default recurring billing schedule of 8pm UTC.
How can I link a payment intent back to the subscription?
If you include metadata in your subscription request to query while retrieving payment intentions, the id will be listed in the subscription_id object.
Another approach would be to watch webhooks for the event payment_intent.succeeded, which includes the payment_intent_id and subscription_id.