What are the toll-free number prefixes?

Q. How do I know if a phone number is a toll-free call? What prefix or prefixes mean toll free?

Adam answers:

If the phone number you are calling begins with the prefix 800, 888, 877, 866, or 855, it is a toll-free phone number. If the number does not begin with one of those prefixes, you will be paying for the call.

800 was the original prefix for toll-free numbers. As the popularity of toll-free numbers grew, the other prefixes were added over time.