What is what area code is 866?

Area code 866 is a toll-free telephone number area code in the North American Numbering Plan (NANP). This means that calls to 866 numbers are free for the caller; the recipient pays the charges. It's not geographically associated with a specific region like other area codes; instead, it's used nationally across the United States, Canada, and some Caribbean islands. Essentially, businesses and organizations use 866 numbers for their customer service lines, marketing campaigns, and other purposes where they want to provide a free number for people to call them.