An entity that enables potential policyholders to complete a single online proposal and obtain quotes from several different insurers NOT associated with the entity is known as

The description provided refers to an insurance aggregator, which is an entity that collects and organizes quotes from multiple insurers, allowing potential policyholders to compare options and obtain insurance coverage conveniently. This model facilitates a streamlined process for customers by enabling them to fill out a single online proposal and receive quotes from various insurers that are independent of the aggregator.

Insurance aggregators play a vital role in the market by promoting competition among insurers and providing consumers with the means to make informed decisions based on coverage and pricing information from different providers. This approach democratizes access to insurance products and empowers consumers in their purchasing decisions.

Other entities listed do not fulfill the same function. For instance, a data controller refers to an entity that determines how personal data is processed, a mutual insurer is owned by its policyholders, and a tied agent represents a specific insurer, thus lacking the independence to provide quotes from multiple insurers. This distinction highlights how the insurance aggregator uniquely serves a vital role in the industry, making the understanding of this term essential for anyone studying the insurance landscape.