In the Orb API, you can now configure credit ledger entries so they're granted after an invoice payment is successful. You can do this by setting invoice_settings.require_successful_payment as true when you create a ledger entry. The block will have status="pending_payment" in the /customers/<id>/credits response.

This behavior is supported for ad-hoc credits or automatic top-up credits. If your customer has a credit block that is waiting on a payment, you will see it in the Orb web app in the "Credit block details" section on their customer page. The block will have "pending payment" noted in the current balance column.