A retrieval fee is a charge that an acquirer or payment processor may levy on a merchant when it handles a retrieval request. A retrieval request, sometimes called a soft chargeback, is sent by the card issuer when a cardholder does not recognise a transaction or questions it, and asks the merchant for a copy of the sales record, receipt or order details. No money moves at this stage, but the acquirer has to receive the request, notify the merchant and return the documents within the network's deadline.
The fee covers that handling and is set by the acquirer's pricing schedule, not by the card networks. It is usually much smaller than a chargeback fee. Responding fully and on time matters more than the fee, because a merchant that ignores a retrieval request may lose the right to contest a later chargeback on the same transaction.