Toll-free telephone number
A Zenith number was typically available from a predefined area, anything from a few nearby cities to a province or state, and was listed in local directories in each community from which the subscriber was willing to accept the charges for inbound calls.
[6] An automated toll-free service was introduced by AT&T in 1966 (US intrastate) and 1967 (US interstate) as an alternative to operator-assisted collect calling and manual "Zenith" or "Enterprise" numbers.
The system initially provided no support for Automatic Number Identification and no itemised record of calls, instead requiring subscribers to obtain expensive fixed-rate lines which included some number of hours of inbound calling from a "band" of one or several U.S. states or Canadian provinces.
Early InWATS 800 calling lacked the complex routing features offered with modern toll-free service.
Despite its limitations (and the relatively high cost of long distance in that era), the system was adequate for the needs of large volume users such as hotel chains, airlines and rental car firms which used it to build a truly national presence.
In the United States, AT&T engineer Roy P. Weber from Bridgewater, New Jersey patented a 'Data Base Communication Call Processing Method' which was deployed by AT&T in 1982.
[7] This feature and other advances that made it possible were what led to AT&T marketing analyst Dodge Cepeda from Bedminster, New Jersey to propose the introduction of providing 800 Toll-Free Service to small and medium-size business customers on a nationwide basis.
Once this service was implemented, it became possible for the very smallest of business operations to have potential customers contact them free of charge at a time when long-distance calling was expensive.
An easily remembered number is valued as a branding and direct response tool in business advertising.
[12] Another example is Mark Russell's 1‑800‑GREATRATE, a shared-use number rented to lenders in various cities nationwide for a monthly fee.
The automaker unsuccessfully sued MBZ Communications of Owatonna, Minnesota, operated by former Mercedes dealer Donald Bloom, alleging deception and trademark infringement.
There are also technical limitations; voice over IP users in particular are difficult to geolocate as their calls may be gated to the public switched telephone network at a point hundreds or thousands of miles away from their actual location.
In addition to NANP toll-free numbers, carriers Bell Canada and Telus offer 310- numbers that can be accessed at local-call prices as shared-cost service (free from landlines, incurs local airtime charge from mobiles and local price from payphones).
There are a few special mobile-only numbers (like *CAA to call the Canadian Automobile Association) which are free from cell phones, these are actually vertical service codes.
Certain helplines, such as those in the 0808 80x xxxx series had remained free from most networks on a voluntary basis and some niche operators, such as Giffgaff always offered freephone calls at no charge.
A three-year transition period prior to that had allowed existing subscribers to migrate to matching 080 85 numbers with the same final 6 digits as before.
[40] Direct inward dialing and toll-free number portability are supported; various providers offer gateways which receive free phone calls on PRI lines and deliver them to voice over IP or pager users.
As of March 2020, 144 carriers in 67 countries participate in the UIFN program;[42] free access to the numbers (as international calls) from mobile and coin telephones is not universal.
Registration of a +800 number incurs a 300 Swiss franc ITU fee (as of 2018) in addition to any charges levied by the individual carrier.
The +808 Universal International Shared Cost Number (UISCN), billed at the price of a domestic call, shares the same eight-digit format; the +979 Universal International Premium Rate Number (UIPRN), billed at a high premium cost, carries one extra digit to indicate price range.
