WATS (wide-area telephone service) is a specialized form of fixed-rate long-distance telecommunication service. WATS lines are commonly used by businesses and government agencies. Some individuals and small corporations also have WATS subscriptions.
There are three types of WATS lines: IN-WATS (for incoming calls), OUT-WATS (for outgoing calls), or a combination of both services. IN-WATS lines have telephone numbers with certain area codes reserved expressly for that purpose, such as 800, 888, or 877. People calling these numbers are not charged a long-distance toll. Instead, the recipient (subscriber) is charged a fixed monthly rate up to a certain number of hours of usage. Beyond the limit, an additional toll is imposed. OUT-WATS lines are, in effect, fixed-rate long-distance subscriptions.
With most WATS lines, calling-zone restrictions apply. For example, it might not be possible to make or accept WATS calls to or from locations within the state where the subscriber is located, or to or from locations outside the country where the subscriber is located.