What Are the Toll

History
Toll-free phone numbers have allowed companies' customers to call them for free since 1967.
Function
Toll-free phone numbers are literally just a more automatic alternative to collect calling. They have found modern usage primarily in increasing customer satisfaction for businesses that want to allow their customers to call them for free.
Prefixes
The toll-free prefixes are 800, 866, 877 and 888. Other numbers have been reserved for future expansion, including 822, 833, 844, 855, 880 through 887 and 889.
Availability
Toll-free phone numbers are available to anyone, not just companies. It is even possible to have your home phone line be a toll-free number.
Warning
Not all phone numbers that start with '1-8' are toll-free numbers; some local prefixes also begin with an '8.' Also, 900 numbers aren't toll-free; they are often more expensive than long-distance calls. Calls made to toll-free numbers using a cell phone are charged at their normal rate.