The emergence of digital financial services and open banking has made it necessary to handle user data in a secure and moral manner. In this changing environment, financial aggregators-platforms that combine financial data from various sources play a critical role. But they frequently run into issues with data portability, privacy, and user consent. This study investigates how Decentralized Identity (DID) systems can improve data portability and change consent processes in financial aggregators. Blockchain-based identification frameworks provide users more control over their data, increase the transparency of permission, and facilitate smooth data transfer between platforms. Through use-case scenarios, technical design, and policy concerns, the study explores the present inadequacies in consent management, presents the DID principles, and demonstrates its potential.