Overview

Apply a customer's credit balance to an open or past-due invoice. If the credit covers the full amount due, the invoice is marked as paid. Otherwise the balance is partially applied and the amount due is reduced.

Behavior

• Only works on open or past_due invoices
• Returns 400 if the customer has no credit balance
• Returns 400 if the invoice is already paid, voided, or uncollectible
• When fully paid, fires the invoice.payment_succeeded event
• The customer's balance is debited by the applied amount