Neustar, Inc. is an American technology company that provides real-time information and analytics for the Internet, telecommunications, entertainment, and marketing industries, and a provider of clearinghouse and directory services to the global communications and Internet industries. Neustar is the domain name registry for .biz, .us (on behalf of United States Department of Commerce), .co, and .nyc top-level domains.

Neustar was incorporated in Delaware in 1998. Neustar started as a business unit within Lockheed Martin Corporation. It spun off to keep the neutrality that was essential to its original core contract with the nation's telecommunications providers.

In November 2006, Neustar completed the acquisition of Followap, Inc., a U.K.-based enabler of mobile instant messaging services.

In 2010, Neustar named Lisa Hook as President and Chief Operating Officer. In January 2010, The Washington Post reported that under Hook's leadership, Neustar was chosen by a consortium of Hollywood studios and technology executives to manage a system whereby consumers could access movies and other video entertainment from multiple digital devices.

In October 2011, Neustar acquired TARGUSInfo.

On October 30, 2013, Neustar announced it purchased Aggregate Knowledge, a seven-year-old ad-tech firm, for $119 million.

In March 2014, Neustar acquired .CO Internet for $109 million.

On September 9, 2015, Asset Purchase Agreement between Transaction Network Services, Inc. and Neustar, Inc.

On June 21, 2016, Neustar Announced Intention to Separate into two independent publicly traded companies.

Within the United States and Canada, Neustar administers the North American Numbering Plan, the authoritative directories that manage virtually all telephone area codes and numbers, and enables the routing of calls among thousands of competing communications service providers (CSPs). All retail telephone companies must access the Neustar clearinghouse to properly route virtually all of their customers' calls. Neustar also provides clearinghouse services to emerging CSPs, including Internet service providers (ISPs), mobile network operators, cable television operators, and voice over Internet protocol (VoIP) service providers.

Neustar offers internal and external managed DNS services that play a role in directing and managing traffic on the Internet, cloud-based DDoS attack protection and website performance management tools. Neustar manages the authoritative directories for the .us and .biz Internet domains, and acts as the worldwide "registry gateway" for China's .cn and Taiwan's .tw Internet domains outside of these two countries. Neustar also provides back end registry services for .co Top Level Domain. Neustar manages a collection of these directories that maintain addresses to direct, prioritize and manage Internet traffic, and find and resolve Internet queries and top-level domains on behalf of its enterprise customers. Neustar serves as the provider of registry services and manages directories of similar resources, or addresses, that its customers use for access and connectivity.

Neustar previously operated the authoritative directory for U.S. Common Short Codes, part of the short messaging service (SMS) relied upon by the U.S. wireless industry, and provides solutions used by mobile network operators to enable mobile instant messaging for their end users. CTIA granted that contract to iconectiv, who took over providing Common Short Code (CSC) Registry Services on January 1, 2016.

Neustar provides the Digital Rights Locker for the consortium of Hollywood studios, consumer electronics manufacturers and retailers behind the UltraViolet digital content scheme to provide consumers with "buy once, play anywhere" capabilities. Neustar is also working with the Open Mobile Video Coalition (OMVC) to manage the Mobile DTV Trust Authority (MDTV.). The MDTV will issue a hierarchy of digital certificates and provide secure, efficient, and easy-to-use online systems to manage the full lifecycle of Mobile DTV trust relationships from registration to ordering, delivery, authentication, status checking and revocation.