A Partial Approval Purchase can be refunded using the Refund transaction. However, you must process a separate refund for each partially approved amount that made up the total Purchase amount. Each amount must be refunded to the specific card from which the funds were drawn, or refunded as cash if cash was used to pay for a specific portion of the total purchase.
For example, if a partial approval was processed for a total of $57.75 using two pre-paid cards, one for $20 and another for $30, with the remaining balance of $7.75 paid as cash, you would need to perform three separate refunds:
a debit/credit refund for $20 using the $20 pre-paid card;
another debit/credit refund for $30 using the $30 pre-paid card; and
a cash refund transaction for $7.75
You can also refund a portion of each individual amount (example, refund $10 to the $20 pre-paid card) using the same guidelines, that is, you must return the money to the specific tender type it was drawn from.
General guidelines for performing transactions