A banking aggregator is a company that connects to many banks and other financial institutions, collects a customer's account data with their consent, and either shows it in a single view or passes it on to other apps and lenders. It is also called a data aggregator or financial data aggregator, and the activity it performs is explained in full in the Account Aggregation entry.
Aggregators usually work behind the scenes. A budgeting app, lender or accounting tool connects to one aggregator rather than building separate links to thousands of banks. Early aggregators relied on screen scraping with the customer's login details; in the EU and UK most now connect through regulated open banking interfaces as an account information service. India has a separate licensed model in which Reserve Bank of India-regulated "account aggregators" pass data between institutions on the customer's instruction without being allowed to store or read it.
Because aggregators hold data from many sources, they raise questions of consent, security and liability that fall under data privacy rules.