Toll-free telephone number
A toll-free telephone number or freephone number is a telephone number that is billed for all arriving calls instead of incurring charges to the originating telephone subscriber. For the calling party, a call to a toll-free number from a landline is free of charge.
A toll-free, Freecall, Freephone, 800, 0800 or 1-800 number is identified by a dialing prefix similar to a geographic area code, such as 800. The specific service access numbers vary by country.
- 1 History
- 2 Vanity numbering
- 3 Around the world
- 4 Universal International Freephone numbers
- 5 See also
- 6 References
The features of toll-free services have evolved as telephone networks have moved from electro-mechanical call switching to fully computerized stored program controlled networks.
Originally, a call billed to the called party had to be placed through a telephone company operator as a collect call. The operator had to secure acceptance of the charges at the remote number before manually completing the call.
A few large businesses and government offices received large numbers of collect calls, which proved time consuming for operators.
Manual toll-free systems
Prior to the development of automated toll-free service many telephone companies provided a manual version of caller free service.
Examples of operator-assisted toll-free calling include the Zenith number introduced in the 1950s in the US and Canada, as well as the original manual 'Freephone' service introduced by the British Post Office in 1960.
Both systems were similar in concept. The calling party would ring the operator (now '100' in the UK, '0' in Canada/USA) and ask for a specific free number. In the US, the caller would ask for a number like "Zenith 1-2345" (some areas used "Enterprise" or "WX" instead of "Zenith", but in the same pattern of a free service name and a five-digit number). In the UK, the caller would ask the operator to ring "Freephone" and a name or number (such as "Freephone Crimebusters" to pass on tips about a crime to the constabulary).
In either case, the operator would look up the corresponding geographic number from a list and place the call with charges reversed.
A Zenith number typically was 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.
Until the introduction of InWATS toll-free service by the Bell System on May 2, 1967 and the Linkline (later "Freefone") 0800 services by British Telecom on 12 November 1985, manually ringing the operator was the standard means to place a toll-free call. More than a few established manual "Freephone" or "Zenith" numbers remained in use for many years after competing automated systems (0800 in UK, 1-800 in US) were deployed in parallel for new toll-free numbers.
Initial direct-dial systems
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. This Inward Wide Area Telephone Service (InWATS) allowed calls to be made directly from anywhere in a predefined area by dialling the prefix 1-800- and a seven-digit number.
The system was primitive by modern standards. It initially provided no support for Automatic Number Identification and no itemised record of calls, instead requiring subscribers obtain expensive fixed-rate lines which included some number of hours of inbound calling from a "band" of one or multiple US states or Canadian provinces. Early InWATS 800 calling lacked the complex routing features offered with modern toll-free service. The three digit exchange following the 800 prefix was linked to a specific destination carrier and area code; the number itself corresponded to specific telephone switching offices and trunk groups. All calls went to one central destination; there was no means to place a toll-free call to another country.
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 hire car firms which used it to build a truly national presence.
For small regional businesses who received few long-distance calls, the original InWATS was prohibitively expensive. As a fixed-rate bulk service requiring special trunks, it was suited only to large volume users.
Modern direct-dial systems
Modern toll-free service became possible when telephone companies replaced their electro-mechanical switching systems with computerized switching systems. This allowed toll-free calls to be routed based on instructions located in central databases.
In the United States, AT&T engineer Roy P. Weber from Bridgewater, New Jersey patented a 'Data Base Communication Call Processing Method' which was initially deployed by AT&T in 1982. The called number was an index into a database, allowing a 'Toll-Free Call' or '800 Call' to be directed anywhere.
In the United Kingdom, BT introduced "Linkline" on 12 November 1985. No more need to manually ring the operator, two new prefixes 0800 (an automated toll-free service which became "Freefone") and 0345 (a shared-cost service marketed as "Lo-Call" because initially its rates resembled those of local calls) could be reached by direct dial. Cable and Wireless used 0500 and 0645, in much the same way, just a few years later.
A toll-free vanity number, custom toll-free number, or mnemonic is easy to remember; it spells and means something or it contains an easily-recognised numeric pattern. An easily remembered number is valued as a branding and direct response tool in business advertising.
In North America, U.S. FCC regulations state that allocation of numbers is first come, first served; this gives vanity number operators who register as RespOrgs a strong advantage in obtaining the most valuable phonewords, as they have first access to newly disconnected numbers and to newly-introduced toll-free area codes. In Australia, premium numbers, such as the 13-series or the vanity phone words, are distributed by auction separately from the administrative procedure to assign random, generic numbers from the available pool.
In toll-free telephony, a shared-use number is a vanity number (usually a valuable generic phoneword) which is rented to multiple local companies in the same line of business in different cities. These appear in Australia (1300 and 1800) and North America (1-800- and its overlays); in the U.S., the RespOrg infrastructure is used to direct calls for the same number to different vendors based on the area code of the calling number.
As one example, a taxi company could rent shared use of 1-800-TAXICAB in one city. The number belongs to a company in Van Nuys, California, but is redirected to local cab companies on a city-by-city basis and promoted by being printed on everything from individual taxi cab hub caps to campaigns against drunk driving. Another example is Mark Russell's 1-800-GREATRATE, a shared-use number rented to lenders in various cities nationwide for a monthly fee.
One former Mercedes dealer obtained 1-800-MERCEDES, charging other dealers to receive calls to that number from their local areas. The auto maker unsuccessfully sued MBZ Communications of Owatonna, Minnesota, operated by former Mercedes dealer Donald Bloom, alleging deception and trademark infringement. Mercedes was ultimately forced to obtain a different number, 1-800-FOR-MERCEDES, for its national call centre.
A company renting 1-800-RED-CROSS at a premium price to individual local Red Cross chapters as 'shared use' was less fortunate; the Federal Communications Commission reassigned that number to the Red Cross as an emergency response to Hurricane Katrina in 2005.
Shared use can be used as a means to circumvent restrictions on warehousing, hoarding and brokering toll-free numbers as technically the number is not being sold, only rented one city or region at a time. The practice is nonetheless potentially problematic as it leaves local businesses advertising numbers which they do not own and for which they therefore have no number portability. The cost per minute and per month is typically far higher for a shared-use number than for a standard toll-free vanity number which a local business controls outright and there is little protection if the shared use company fails to meet its obligations or ceases operation.
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. A roaming mobile or Internet telephone user is effectively (like the user of a foreign exchange line) attached to a distant rate centre far from their physical address.
If a programme like Crime Stoppers is inherently regional or local, but the same national 1-800-222-TIPS number is shared between multiple Canadian and US call centres, the centre accepting the call must determine whether the call belongs to some other region.
Around the world
|This section needs additional citations for verification. (February 2014)|
Countries around the world use different area codes to denote toll-free services in their own networks. Some examples are:
- In Argentina, the prefix for toll-free numbers is "0800", followed by seven digits (the first three of them are fixed for each operator, so the user may know which carrier is serving the party they are calling). These numbers are called "0-800" (cero ochocientos) or "líneas gratuitas" (free lines). There is also a local-rate service named "0-810" (cero ochocientos diez) where the calling party pays the fee for a local call and the called party pays for the long distance fees.
- In Armenia, the toll-free prefix is "800" followed by a five-digit number.
- In Austria, the prefix for toll-free numbers is also "0800", but only followed by six digits. They are commonly referred to as "Null-achthunderter Nummern" (Zero-eighthundred numbers).
- In Belgium, the prefix "0800" is used for toll-free numbers, followed by 5 digits. They are commonly referred to as "Groen nummer" (Dutch) and "Numéros verts" (French) or "Null-achthunderter Nummern" (Zero-eighthundred numbers) in the German speaking area.
- In Brazil, The prefix is "0800" - although phone numbers are 8 digits - it is followed by 7 digits - 6 digits are being phased out. Toll-free numbers in Brazil can be accessed from any telephone (by default) in Brazil, with many exceptions. They can be accessed from outside Brazil only with a calling service (such as voice-over-Internet services or MCI Worldcom calling service) that accesses numbers from within the called country. Many toll-free numbers are not available from cell phones (usually blocked by the cell phone provider rather than the provider of the toll-free number in an effort to prevent low-price competition from calling card providers). Some toll-free numbers are not available from phones listed by the owner of the number, including many payphones. For example, the MCI Worldphone calling service blocks usage from the pay phones in international airports (Rio and São Paulo) and many downtown pay phones due to "excessive fraud" from those phones (July 2003). In addition, Brazil has a system of regular and international pay phones (designated with the symbol "DDD"). Toll-free numbers to international calling plans can be reliably used from non-DDD pay phones, as of 2005.
- In Bulgaria, the toll-free prefix is "0800" followed by a five-digit number (up to now, only 1XXXX and 20ххх numbers have been allocated). These numbers are called "Зелен номер" (Green Number) by BTC and "Зелена линия" (Green Line) by M-tel.
- In Canada, toll-free numbers are drawn from the US SMS/800 database. A seven-digit number 310-xxxx (not a true toll-free, but may be called from anywhere in its home area code at local rates) is available in Bell Canada territory. From a landline, these are free.
- In Chile, the toll-free prefix is "800" followed by a six-digit number. These numbers are called "número 800" (800 number). These numbers can not be accessed from abroad.
- In Colombia, toll-free numbers start with 018000
- In Croatia, the prefix for toll-free numbers is "0800"
- In Czech Republic, the toll-free prefix is "800".
- In Denmark telephone-numbers have eight digits. The toll-free numbers all begin with "80" followed by six further digits.
- The Dominican Republic is assigned specific 1-800 exchanges in the North American Numbering Plan; the 1-809-200-xxxx exchange is also free for domestic callers in that country.
- In Egypt, it starts with (800) followed by the number.
- In Ecuador, it starts with 1800 followed by 6-digit number. Some numbers have either regional or nationwide access. Calls from cellphones are only allowed by the operator Alegro which charges a few cents for these calls. PORTA and movistar does not allow the service.
- In France the "0800" or "0805" prefix is used for toll-free numbers. They are also known as numéros verts (green numbers).
- In Finland, the toll-free prefix is "0800".
- In Germany, the toll-free prefix is "0800" followed by a seven-digit number. The "0801" prefix is already reserved for future use. The prefix was formerly "0130". Deutsche Telekom calls these numbers "freecall 0800", most Germans refer to it simply as "Null-achthunderter Nummern" (Zero-eighthundred numbers).
- In Greece, the toll-free prefix is "800" followed by a seven-digit number or "807" followed by a four-digit number, used for phonecard services only.
- In Hong Kong, toll-free numbers have "800" prefix
- In Hungary, toll-free numbers have "80" prefix.
- In Iceland, the toll-free prefix is "800" followed by a four-digit number.
- In India, the toll-free prefix is "1800" followed by an seven-digit number. Free if calling from a mobile phone. Calling from land-line and VoIP will be considered a local call, with varying charges depending on the land-line and VoIP network providers.
- In Indonesia, the toll-free prefix is "0800" followed by a seven-digit number.
- In Ireland, 1800-xxxxxx numbers are freephone, with the 1800 71xxxx reserved for services that expect unusually high volumes of calls e.g. radio station phone-in lines.
- In Israel, toll-free numbers are prefixed with "1800" followed by 6 digits (for local businesses), "180" or "189" followed by 7 digits (usually refers to a free call to an overseas operated calling center). The called party pays the charges for the call. As of 2012 calls from local cellular phone service providers to these prefixes are also free. Numbers prefixed with "1700" followed by 6 digits are local rate number for the first 3-4 minutes after which the charges for the remaining length of the call are transferred to the receiving party (on a "shared cost" basis).
- In Italy, toll-free numbers are dialed with the "800" or "803" prefix and are commonly referred to as "Numero Verde" (green number) or "Linea Verde" (green line). The "Numeri Verdi" used to begin with "1678" and later with "167".
- In Japan, the prefixes "0120" and "0800" are officially assigned for toll-free numbers and are often referred to as "free dial" (フリーダイヤル?) or "free call" (フリーコール?) telephone numbers. Several telephone carriers also provide toll-free services under their own company prefixes such as "0077" (these prefixes are also used for other tolled services; the prefix "0570" is officially assigned for Navi Dial, a special tolled service).
- In South Korea, toll-free numbers are prefixed with "080" (not to be confused with "060" or "070", which are used for pay-per-call/pay-per-minute information services or digital home phone services). It is to be noted that not all numbers with the "080" prefix are toll-free when called from a mobile phone.
- In Latvia the prefix 8000-xx-xx is used for toll-free services. They are toll-free only when dialed from landlines, and charged the same as a land line when dialed from cell phones.
- In Malaysia the prefix is 1800-xxxxxx. Free if calling from a land-line and VoIP only. Calling from mobile phone will be considered a local call, with varying charges depending on the mobile network providers.
- In Mexico the prefix is 01-800.
- In Nepal the prefix is 1660-01-XXXXX.
- In New Zealand, both "0800" or "0508" prefixes are referred to variously and interchangeably as "free phone" or "toll-free". Originally these "Oh-eight-hundred" numbers were provided by Telecom NZ and "0508" by rival company Clear (now Vodafone New Zealand), although now both numbers can be provided by either company. Some older toll bar services designed to restrict toll calls (including long distance or calls to mobile phones) will also block calls to these free phone numbers, although this has become less common since the mid-1990s. A limited number of companies utilizing toll-free numbers will not accept calls from mobile phones. Some other free phone services exist, such as "*555" ("star five five five"), which can be dialled from cellular phones to report traffic conditions and incidents of dangerous driving.
- In the Netherlands, the prefix "0800" is used for toll-free numbers. Calling 0800 numbers from fixed- and mobile phones is free by law. UIFN's "00800" are generally free from fixed lines and charged for the air-time from mobile phones. Access of UIFN is not enforced by law, causing certain phone providers to not honor the standard.
- In Norway most telephone-numbers have eight digits (some exceptions). The toll-free numbers all begin with "800" followed by five further digits.
- In Pakistan,toll-free numbers have the following format "0800-xxxxx".
- In Paraguay, the prefix "0800" is used for toll-free numbers, followed by 6 digits.
- In the Philippines, the prefix for toll-free numbers is "1800" followed by either one, two, or four digits (examples include 8, 10, and 1888) followed by either a four- or seven-digit phone number. However, there are restrictions. Toll-free numbers are only limited to the telephone network where the toll-free number is currently being handled. So subscribers of a different telephone network company will not be able to call the toll-free number handled by a different telephone network. International toll-free numbers can only be accessed if the calling party is a subscriber of PLDT.
- In Poland, toll-free numbers have the following format "800 xxx xxx". There are also Split-Charge numbers "801 uxx xxx" (caller's cost depends on the digit u) and Universal Numbers "804 uxx xxx", where the caller is automatically connected to the nearest office (are toll-free if u=3).
- In Portugal, the prefix is "800" so the 9-digit number is "800 xxx xxx". It is referred as "Chamada Gratuita" (Free Call) or as "Número Verde" (Green Number).
- In Qatar, toll-free numbers have the following format "800 xxxx".
- In Romania, toll-free numbers have the following format "0800 xxx xxx". The service is referred to as "Număr Verde".
- In Russia, the prefix is "8" "800", followed by 7 digits (8-800-XXX-XX-XX).
- In Serbia, the prefix "0-800" followed by a 6 or 7 digit number is used
- In Singapore, the prefix "1800" followed by a 7 digit number is used. Calling from a mobile phone network will be considered as a local call and charges varies among service providers.
- In Slovakia, the toll-free prefix is "0800", followed by six digits. The local rate prefix is "0850".
- In Slovenia, the prefix "080" is used for toll-free numbers, followed by four more digits.
- In South Africa, the prefix "0800", followed by 6 digits is used. It is referred to as a "toll-free" or "0800" number (Afrikaans: tol-vrye).
- In Spain, the "900XXXXXX" or "800XXXXXX" numbers are always toll-free (800 numbers are not usually used), "909XXXXXX" is used for dial-up Internet service and toll-free dialup Internet service (under subscription). Also "1002", "1004", "14XX", "15XX" and "16XX" are free and are used for the telecommunication providers call centers.
- In Sweden, the prefix is "020" or "0200" for toll-free numbers. (Additionally, 0800 is reserved for future use.) These numbers are unreachable from other countries.
- In Switzerland, the toll-free prefix is 0800; previously it was 155. These numbers are called « grüne Nummer / numéro vert / numero verde » (green number).
- In Taiwan, the toll-free prefix is 0800-xxx-xxx or 0809-xxx-xxx, but not all Taiwanese mobile number can call the toll free numbers. A toll-free subscriber can decide to restrict a number due to high per minute mobile rates. This is cumbersome for the caller, who is told to dial another land line number, usually at the highest toll rate within the country as a mobile to landline call. Some small VOIP operators also cannot call toll free numbers. (0701-xxx-xxx cannot call toll free numbers directly, but can call through a live operator by dialling "123" and have them redirect the call).
- In Thailand, Call Free, Free Call, Toll-Free, or Free Phone,the prefix used is "1800"xxxxxx. Calls are free for all fixed line calls. Mobile carriers AIS and CAT (60+%of Thailand's subscribers) offer 1-800 service for cell phones. At present DTAC and True mobile providers do not, however it is expected they will offer the 1-800 service for subscribers by late 2009.[dated info]
- In Turkey, the prefix for toll-free numbers is "0800".
- In the UK, Freephone numbers are usually only free when calling from a landline. All 0500 numbers have 9 digits, 0808 numbers have 10 digits and 0800 numbers have 7, 9 or 10 digits after the "0" trunk prefix.
- In Ukraine, toll-free numbers have "0" "800" and 6 digits after, i.e. 0 800 123456. Before October 2009 "8" "800" prefix was used.
- In Vietnam, the prefix "1800" followed by a series of numbers, usually from 4 to 9 digits. All "1800" numbers are free of charge, but some of them cannot be dialled from all telephones.
Toll-free numbers in the North American Numbering Plan (NANP) are commonly called "800 numbers" after the original area code which was used to dial them. They include the area code 800 (since 1966), 888 (since 1996), 877 (since 1998), 866 (since 2000), 855 (since 2010), and 844 (December 7, 2013). Area codes reserved for future expansion include 833, 822, 880 through 887, and 889.
These are free from regular phones but incur cellular airtime charges from mobile telephones. There are a few special mobile-only numbers (like *CAA to call the Canadian Automobile Association) which are free from mobile.
The original Wide Area Telephone Service is obsolete. North American toll-free numbers are controlled by an intelligent network database (SMS/800) in which any toll-free number may be directed to a local or long-distance geographic telephone number, a T-carrier or primary rate interface line under the control of any of various RespOrgs. Direct inward dialing and toll-free number portability are supported; various providers offer gateways which receive freephone calls on PRI lines and deliver them to voice over IP or pager users.
Toll free numbers usually capture the telephone number of the caller for billing purposes through automatic number identification, which is independent of caller ID data and functions even if caller ID is blocked.
- Calling an 800 number is free of charge. Calling a 400 number incurs a local access charge.
- 800 numbers are accessible only to land-line subscribers, while 400 numbers are accessible to all land-line and mobile users.
800 toll-free numbers
- 800 toll-free numbers are commonly called "800 免费电话". The official name is "被叫集中付费业务" (called party collect paid service), which means the cost of the call is borne not by the caller but by the party receiving the call.
- 800 toll-free numbers in China are ten-digit numbers beginning with "800". There is no prefix before "800".
- 800 toll-free numbers are not accessible to mobile network subscribers and some land-line subscribers. For instance China Tietong Telecom land-line users cannot access 800 numbers.
400 toll-free numbers
- 400 service is called "主被叫分摊付费业务" (calling party and called party split-paid service), which means the calling party pays for the local access fee and the called party pays the toll (long distance) fee.
- 400 toll-free numbers in China are ten-digit numbers beginning with "400".
- 400 toll-free numbers can be accessed by all fixed-line and mobile phones.
- Callers have to bear local access charges from their service providers.
- 400 toll-free numbers with prefix "4001" are international toll-free numbers which can be routed to destination numbers inside or outside of China. 400 toll-free numbers with prefix "4000", "4006", "4007" or "4008" are national toll-free numbers which can be routed to China destination numbers only.
Toll-Free (usually referred to as Free Call or Free Phone)
- Toll-Free numbers in Australia are ten-digit numbers beginning with the prefix "1800".
- 1800 numbers can be also found in Phonewords via an online auction.
- For all types, the recipient business pays for incoming toll charges.
- In some cases, 1800 numbers can be accessed from international lines.
- Callers to an 1800 number are not charged a connection fee from a domestic fixed line. Calls from a mobile phone may incur charges depending on the provider.
Local Rate numbers
A system similar to 1800 numbering exists where 6 or 10 digit numbers prefixed with 13 (one-three), 1300 or 1301 (colloquially one-three-hundred) can be called at local call rates regardless of location.
- Callers to 13 number are charged a "connection fee" by their telephone provider.
- 13 and 1300 numbers are often "smart routed" to the local outlet of chain stores or fast food premises. They may also be used by different companies in different regions.
- 13 numbers, 1300 numbers and 1800 numbers are relocatable across Australia, and can be transferred between different telecommunications suppliers.
- 13 numbers are a premium number scheme, subject to charges from the Australian Communications and Media Authority (ACMA) of approximately $10,000 per annum collected by the supplying carrier.
- Premium numbers, such as those that spell a word using keypad letters, are regularly auctioned by the ACMA
- Mobile callers are charged to phone a 1300 number or 1800 number, usually at their normal per minute rate, but sometimes at predatory rates. These expensive numbers can be decoded to ordinary landline via http://www.e164.org/non-search.php and organisations usually offer a landline number on their websites, though it may be hard to find.
- Smart routed 1800 or 13(00) numbers often do not work on mobile telephone due to issues with owners of the numbers barring incoming calls from mobile devices due to higher call charges associated with such calls.
In the United Kingdom, toll-free telephone numbers are generally known as "freephone" numbers (British Telecom numbers are officially Freefone) and begin with the prefixes 0800, 0808 or the Cable & Wireless Freecall prefix 0500. The most commonly used prefix is 0800. Additionally, numbers in the range 0808 80x xxxx are reserved for not-for-profit helplines.
0800 and 0808 are free for landline users, but may cost up to 41p per minute from mobile telephones. Mobile operators must announce at the start of a call that charges apply, but are not required to announce the price of the call.
Since Orange UK introduced charges for dialling freephone numbers in December 2005, all British mobile networks (excluding giffgaff who are an MVNO) now charge for calls to freephone numbers, with certain limited exemptions (notably 0808 80x xxxx numbers, DWP new claims, Childline and some other services), but this varies by network.
Freephone 0800 and 0808 numbers will become free calls from all UK mobile phones on 26 June 2015. The UK mobile operators offer an alternative product to organisations who wish to provide toll-free services - 5-digit voice short codes which are sold through mobile aggregators.
Freephone 0500 numbers, introduced by Mercury Communications in 1982 (and later Cable and Wireless, now Vodafone), will be withdrawn by Ofcom on 3 June 2017. A three-year transition will allow existing subscribers to migrate to 080 85 numbers with the same final 6 digits. While the numbers are portable, 0500 has been closed to new allocations since 1997/98.
Freephone numbers can be obtained for free, with incoming calls charged from 1 penny per minute. Manual toll-free calls are also still available via the operator, although largely superseded by the 0800 system - a commonly seen phrase in advertisements in the early 1980s was "Dial 100 and ask for freephone <business name>".
Universal International Freephone numbers
A Universal International Freephone Number (UIFN) is a worldwide toll-free "800 number" issued by the ITU. Like the 800 area code issued for the NANP in the U.S. and Canada and 0800 numbers in many other countries, the call is free for the caller, and the receiver pays the charges. UIFN uses ITU country code 800, so that no matter where the caller is, only the international access code (IAC), the UIFN country code (800) and the 8-digit UIFN need to be dialed. Currently, a limited number of carriers in about 65 countries participate in the UIFN program; free access to the numbers (as international calls) from mobile and coin telephones is not universal. Registration of a +800 number incurs a 200 swiss franc ITU fee (as of 2013) in addition to any charges levied by the individual carrier. The number must be activated for inbound calls from at least two telephone country codes within 180 days.
The +800 UIFN service is one of three ITU-administered non-geographic codes with a similar numbering scheme. 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.
- SMS/800 and RespOrg
- 900 number
- Collect call
- Mobile dial code
- Wide Area Telephone Service
- Zenith number
- BT Plc. "Events in Telecommunications History (1960)". BT Archives. BT Group. Retrieved 2009-05-11.
- Blackburn Police Station, Westlothian UK, "dial 100 and ask for Freephone Crimebusters" to report tips about crime
- Weber, Roy P. "Data base communication call processing method". "US patent 4191860. Filed Jul 13, 1978. Issued Mar 4, 1980"
- BT Plc. "Events in Telecommunications History: 1985". BT Archives. BT Group. Retrieved 2011-08-23.
- Robinson-Jacobs, Karen (Nov 28, 2000). "Nationwide Taxi Service Calls Valley Home". Los Angeles Times. p. B1.
- "Logix to Route Callers for 1-800-Taxicab". Direct Marketing News. 2000-11-22. Retrieved 2013-11-04.
- ANDREW ZIPERN (2001-05-14). "MediaTalk; In Los Angeles, the Hubcap as Billboard". New York Times. Retrieved 2013-11-04.
- "Businesses, Sheriff's Office pitch in tonight to get drunks home". Nashville Business Journal. 2009-12-31. Retrieved 2013-11-04.
- "1 800 Mercedes | 1-800-catchy-number- makes-a-lot-of-money". Baltimore Sun. 2004-03-09. Retrieved 2013-11-04.
- "Mercedes says Owatonna firm is dealing on its name". Star-Tribune (Minneapolis-St. Paul). February 22, 2000.
- The United States Patents Quarterly, Page 1361, Associated Industry Publications, 2003
- Kevin Poulsen (Sep 7, 2005). "Red Cross Gets Squatter's Number". Wired.com. Retrieved 2013-07-01.
- "Toll-free lines - Green Line - 800". O2 Czech Republic. Retrieved 2011-07-21.
- "The Numbering Plan for Telecommunications Services in Hong Kong (SAR), China" (PDF). OFCA, Hong Kong. 2014.
- "Numbering plan for Ireland" (PDF). ComReg Ireland.
- "National Toll Free 800 Service". QTel Qatar.
- "Number Resources - NPA (Area) Codes". NANPA. Retrieved 2013-11-04.
- "Toll Free Calls and Telecommunications Tariffs". Phone Services. 11 September 2013. Retrieved 7 February 2014.
- Fallon, Sean (2009-02-17). "TrapCall Displays Blocked Numbers on Your Caller ID". Gizmodo. Retrieved 2012-07-27.
- "Special numbers: Charges for calls to 13, 1300 & 1800 numbers". Australian Communications and Media Authority. 2013-10-11. Retrieved 2013-12-30.
- "smartnumbers". The Australian Communications and Media Authority. Retrieved 2012-04-25.
- "Annual numbering charges". ACMA.
- "Auctioned". ACMA.
- Some Sectoral and Locational Factors in the Development of Call Centres in the USA and the Netherlands, Peter Bain, University of Strathclyde, 2001
- Murray-West, Rosie (2013-04-13). "'Freephone' numbers to be free from all phones". Telegraph (UK). Archived from the original on 2013-04-15.
- giffgaff. "giffgaff prices: UK tariffs". giffgaff.
- Vodafone (2010-10-28). "Free-to-caller charity numbers" (PDF). Vodafone Limited. Archived from the original on 2013-02-22.
- O2. "Free numbers". Telefónica UK Limited.
- Virgin. "Freephone numbers and Charity Helplines". Virgin Mobile Telecoms Ltd.
- T-Mobile (2012-01-30). "Free to Call Helpline Services" (PDF). Everything Everywhere Limited. Archived from the original on 2012-05-03.
- Orange. "Free Charity Numbers". Orange (UK).
- DWP (2010-01-15). "Free mobile calls for benefit claimants starting from 18 January 2010". Department for Work and Pensions.
- Orange (2011-02-01). "Free numbers of Department of Work and Pensions". Orange (UK). Archived from the original on 2011-02-12.
- Ofcom (2013-12-12). "Simplifying non-geographic numbers" (PDF). Final statement. Office of Communications. Archived from the original on 2013-12-12.
- "UIFN". International Telecommunication Union. Retrieved 2013-01-11.
- "UIFN". International Telecommunications Union. Retrieved 2013-11-04.