Editing Wide Area Telephone Service (section)

==InWATS==
{{main|Toll-free telephone number}}
A form of toll-free telephone service in North America was the [[Zenith number]], published in distant cities from where a company expected or desired frequent customer calls. Published as "Zenith" and a four- or five-digit number, these [[collect call]]s required operator assistance. The subscriber of the service was charged for the call.

With "inward WATS", introduced for interstate calls by the [[American Telephone and Telegraph Company]] (AT&T) in 1967, subscribers were issued a [[toll-free telephone number]] in a designated toll-free [[area code]]. Unlike a standard collect call or a call to a [[Zenith number]], 1{{nbh}}800 normally may be dialed directly with no live operator. Callers within a designated area could call without incurring a toll charge as the recipient paid for the calls at a fixed rate.

The introduction of InWATS fortuitously fell around the same time as the early centralized, automated national airline and hotel reservation systems, including [[Sabre Corporation|Sabre]] (American Airlines, 1963), [[Holiday Inn|Holidex]] (Holiday Inn, 1965) and [[Sheraton Hotels and Resorts|Reservatron]] (Sheraton, 1969). Hundreds of local reservation numbers for a major chain could be replaced with one central number, backed by a national computerized reservation system.<ref name=s8003253535>{{Cite web |url=http://www.bluemaumau.org/hotel_history_magic_8003253535 |title=Hotel History: The Magic of 800-325-3535 &#124; BlueMauMau, franchise news for franchisees |access-date=2015-01-28 |archive-date=2018-06-27 |archive-url=https://web.archive.org/web/20180627062608/https://www.bluemaumau.org/hotel_history_magic_8003253535 |url-status=usurped }}</ref>

InWATS exchanges were assigned to Canada and other North American Numbering Plan countries, but the original InWATS in each country accepted domestic calls only. Initially 1{{nbh}}800{{nbh}}NN2{{nbh}}XXXX numbers were U.S. intrastate and specific prefixes (such as 1{{nbh}}800{{nbh}}387 Toronto and 1{{nbh}}800{{nbh}}267 Ottawa) were assigned to Canada.<ref>[https://books.google.com/books?id=1PVZHtB6XAwC&pg=PT146 "800 Number Allocation"], Telecom Informer (February, 1987), Dan Foley, [[2600 Magazine]] reprinted in "The Best of 2600: A Hacker Odyssey - By Emmanuel Goldstein" suggests 1-800-NN7 as Canada, but AT&T routing guides list 1-800-N61, 1-800-N63, 1-800-N65, 1-800-N67 as the most common Canadian toll-free exchange prefixes. There were exceptions to these patterns, but one prefix always identified one specific geographic destination area code in InWATS.</ref> In the 1970s, AT&T's internal routing guides included separate U.S. and Canadian 1-800 exchange maps which looked much like area code maps<ref>[http://www.historyofphonephreaking.org/docs/trg/TRG-1977-Sec02-03.pdf Traffic Routing Guide], AT&T, 1977 matches each area code to one or more specific hard-wired exchanges.</ref> as each geographic area code had one or more specific freephone exchange prefixes. [[Sheraton Hotels and Resorts|Sheraton]]'s 800{{nbh}}325{{nbh}}3535, one of the notable early adopters in late 1969, was hard-wired into [[St. Louis]] [[area code 314]];<ref name="s8003253535"/> 1{{nbh}}800{{nbh}}HOLIDAY at that time could not be a U.S. number if the 1{{nbh}}800{{nbh}}465 prefix was hard-wired to [[Thunder Bay]]'s [[area code 807]]. Any attempt to call a foreign 1{{nbh}}800 gave a pre-recorded error, "the number you have dialed is not available from your calling area."

Like the OutWATS service, AT&T's InWATS was divided into intrastate and interstate, with interstate calls priced into five or six "bands" of calling. This favored placement of US national call centers in low-population Midwestern states such as [[Nebraska]],<ref>{{cite web |title=Atlanta Telephone History |url=http://www.atlantatelephonehistory.info/part4.html |access-date=10 May 2016 |archive-url=https://web.archive.org/web/20160510230658/http://www.atlantatelephonehistory.info/part4.html |archive-date=10 May 2016 |date=8 July 2008}}</ref> whose central location meant a carefully situated "band 3" number reaching halfway across the US in every direction could potentially reach 47 states. A [[San Diego]] call center would be less fortunate; even with "band 6" (the most expensive lines), its national number would be unreachable to millions as [[California]] is a populous state and intrastate calls needed a separate toll-free number.

The original InWATS system was supplanted by "Advanced 800 Service" in the 1980s.<ref>{{cite web | first=Roy P | last=Weber | url=https://patents.google.com/patent/US4191860 | title=Data base communication call processing method (US Patent 4191860) | quote=Filed Jul 13, 1978. Issued Mar 4, 1980}}, devised at Bell Labs and deployed by AT&T in 1982, supplanted InWATS with a flexible intelligent network database which could send any toll-free number anywhere.</ref> Modern systems eliminated requirements tying toll-free numbers to dedicated flat-rate inbound WATS lines. [[Direct inward dial]], introduced in 1983, allowed one trunk to carry calls for multiple numbers. AT&T's monopoly on U.S. toll-free number routing ended in 1986, encouraging flexibility in order to match rivals [[Sprint Corporation|Sprint]] and [[MCI Communications|MCI]]. By 1989, fixed "bands" of coverage area had been largely replaced by distance-based billing, a growing number of 1{{nbh}}800 numbers were being terminated at standard local business or residence lines and one number could be sent to multiple locations based on call origin, least-cost routing or time of day routing.<ref>{{cite journal|url=https://books.google.com/books?id=1hwEAAAAMBAJ&pg=PA25 |title=800 services now a fact of life |journal=Network World |date=July 3, 1989 |access-date=October 31, 2013 }}</ref> [[RespOrg]]s were established in the U.S. in 1993 and Canada in 1994 to provide toll free number portability using the Service Management System ([[SMS/800]]) database.  Calls from Canada and the U.S., intrastate and interstate, could terminate at the same 1{{nbh}}800 number, even via different carriers. [[Vanity number]]s became easier to obtain as a toll-free exchange prefix was no longer tied to a geographic location. By the 21st century, [[Voice over IP]] placed toll-free and foreign exchange numbers into the hands of even the smallest users, to whom dedicated inbound lines under the original InWATS model would have been prohibitively expensive.