All debit and prepaid card processors as well as a limited number of credit card processors
support partial authorizations when using dual message processing.
When partial authorization is enabled, the issuing financial institution can approve a
partial amount when the balance on the card is less than the requested amount. When a partial
amount is authorized, the capture is not processed. This enables the merchant to use a second
card to cover the balance, adjust the total cost, or void the transaction.