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