The refunds function works using automatching, which itself works within several parameters. Automatching will only occur when there is only one transaction between member and merchant available.
In this case, the negative transaction must be equal to or less than the initial positive transaction. Note: Multiple refunds may be made for the same transaction, but the positive transaction must be larger than the negative transactions minus any other refunds already applied for that transaction.
The positive transaction must have occurred before or the same day as the negative transaction.
Both transactions should be with the same merchant, and both transactions should be associated with the same member (this can be with different cards, as long as the card(s) for both transactions are registered.
The transactions must be cleared (transactions cannot be given for authed transactions).
Some transactions will not be automatched and thus have to be processed manually by the Program Operator. Refunds that aren’t automatched will be put into the review state. This could happen if a refund could match more than one positive transaction. In this case, the Program Operator will have to decide which transaction to match the refund with (or not process the refund).
If a refund has been matched (automatically or manually), it can be unmatched in a review state.