A chargeback is when a customer or issuing bank disputes one of your transactions. For example, if a customer has a transaction on their statement that they don’t recognize, they can contact their bank to dispute the transaction. Read more
A retrieval request is when a bank asks you to send information about a transaction that a customer disputed. You receive a retrieval request in the mail.
A retrieval request doesn’t cost you anything, however, not responding to the request leads to a chargeback. Read more