In particular embodiments, computer-implemented data processing, systems, and method configured to: receive a request to initiate a transaction between an entity and a data subject, generate (i) a consent receipt for the transaction comprising at least a unique subject identifier and a unique consent receipt key and (ii) a unique cookie to identify the data subject's transaction initiated by the data subject, store the consent receipt for the transaction and the unique cookie, receive a data subject access request from the data subject, verify an identity of the data subject based at least in part on the unique cookie process the request, process the request by identifying one or more pieces of personal data associated with the data subject, and taking one or more actions based at least in part on the data subject access request.