The toll-free 866 reverse lookup is a feature that allows anyone receiving a call from a toll-free number beginning with 866 to find out the name of the business calling. Reverse lookup gives an individual the opportunity to determine if they wish to call the business back before dialing.
Toll-free numbers often show up on caller ID as unknown numbers.These numbers began to be used in the 1960s. Their popularity continued, with the 866 phone number extension being one of many extensions that allows customers to contact businesses free of charge. In addition to the 866 number, 800, 855, 877 and 888 are all toll-free extensions.