The Adjustment Type indicates whether you want to reverse the entire payment or refund a portion of the payment.

Reversal Select the Reversal option if you want to reverse the entire amount of the payment.
Refund Select the Refund option if you want to refund a portion of the payment. The Refund Amount cannot exceed the Unapplied Amount.

Tip: If the portion of the payment that you want to refund exceeds the Unapplied Amount shown, you will need to select the Reversal option and reverse the entire payment. Then, re-enter the payment with an amount equal to the difference between the original payment amount and the amount refunded to the client.

See also:   Payment Adjustment Overview