411King is an online people-search and reverse phone lookup service designed to help users identify who may be calling them. Its search engine scans a large collection of records to find information associated with a phone number. The site reports access to more than 1.3 billion records, gathered from a wide variety of sources, with new data added around the clock.

Users can enter a phone number to search, create an account, and pay to access a report. Searches are free to initiate, and 411King says customers pay only when results are available. Its team-searching feature is intended to prevent users from paying twice for the same records. The service is presented as a global information resource for phone data, and the site notes that thousands of companies use its services.

In addition to phone lookup, 411King provides a phone directory and information about its terms, privacy practices, and record-removal process. Users can also find help through its FAQs or contact the company with questions.