See also
- Mobile dial code
- Pat Fleet – Prompt voice for most U.S. AT&T implementations of VSC features
- Public switched telephone network
- Short code
A vertical service code (VSC) is a sequence of digits and the signals star (*) and pound/hash (#) dialed on a telephone keypad or rotary dial to access certain telephone service features. [1] Some vertical service codes require dialing of a telephone number after the code sequence. On a touch tone telephone, the codes are usually initiated with the star key, resulting in the commonly used name star codes. On rotary dial telephones, the star is replaced by dialing 11.
In North American telephony, VSCs were developed by the American Telephone and Telegraph Company (AT&T) as Custom Local Area Signaling Services (CLASS or LASS) codes in the 1960s and 70s. Their use became ubiquitous throughout the 1990s and eventually became a recognized standard. As CLASS was an AT&T trademark, the term vertical service code was adopted by the North American Numbering Plan Administration. The use of vertical is a somewhat dated reference to older switching methods and the fact that these services can only be accessed by a telephone subscriber, going up (vertically) inside the local central office instead of out (horizontally) to another telephone company.
The following are the vertical service codes generally recommended by the North American Numbering Plan Administrator for use in the NANP territories. Not all of these services are available in all areas, and some are only available on landline telephones or Mobile phones.
Local Area Signalling Services (LASS) and Custom Calling Feature Control Codes: [2] [1] [3]
| Vertical service code | Service definition | Australia | France | Israel | Japan | UK | |
|---|---|---|---|---|---|---|---|
| Tone dialing | Pulse dialing | ||||||
| *51 | 1151 | Who called me. Provides the directory number, date and time of unanswered calls. | |||||
| *52 | 1152 | Call Hold (Single Line Variety Package). Permits the call to be picked up at another station. | |||||
| *53 | 1153 | Distinctive Ring B. Allows a subscriber to alert a specific party distinctively. | |||||
| *54 | 1154 | Distinctive Ring C. Allows a subscriber to alert a specific party distinctively. | |||||
| *57 | 1157 | Call trace (Malicious caller identification) | |||||
| *60 | 1160 | Call blocking | |||||
| *61 | 1161 | Priority call | |||||
| *62 | 1162 | Selective call waiting | |||||
| *63 | 1163 | Selective call forwarding | |||||
| *65 | 1165 | Calling number delivery activation | |||||
| *66 | 1166 | Continuous redial | |||||
| *67 | 1167 | Calling number delivery blocking | 1831 #31# [4] [5] | 141 #31# [6] | |||
| *68 | 1168 | Activate call forwarding on busy | |||||
| *69 | 1169 | Last-call return (incoming) | *69 HFC *10# [7] [8] | 3131 | *42 | 1361 1363 [9] | 1471 [10] |
| *70 | 1170 | Call waiting disable | |||||
| *71 | 1171 | Usage sensitive three-way call | |||||
| *72 | 1172 | Unconditional forward: All calls | |||||
| *73 | 1173 | Call forward: Cancel | |||||
| *74 | 1174 | Speed calling (8 numbers) | |||||
| *75 | 1175 | Speed calling (30 numbers) | |||||
| *77 | 1177 | Anonymous call rejection activation | |||||
| *78 | 1178 | Do not disturb | |||||
| *79 | 1179 | Do not disturb disable | |||||
| *80 | 1180 | Call blocking disable | |||||
| *81 | 1181 | Priority call disable | |||||
| *82 | 1182 | Caller ID (per call) | *31#/1832 [11] | 1470 | |||
| *83 | 1183 | Selective call forwarding disable | |||||
| *85 | 1185 | Caller ID disable | |||||
| *86 | 1186 | Continuous redial cancel | |||||
| *87 | 1187 | Anonymous call rejection deactivation | |||||
| *88 | 1188 | Deactivate call forwarding on busy | |||||
| *89 | 1189 | Last-call return cancel | |||||
| *90 | 1190 | Conditional forward: Busy line | |||||
| *92 | 1192 | Conditional forward: No answer | |||||
| *94 | 1194 | Directed call pickup | |||||
| *272 | Wireless Priority Service | ||||||
The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the telephone country code 1. Some North American countries, most notably Mexico, do not participate with the NANP.
A telephone keypad is a keypad installed on a push-button telephone or similar telecommunication device for dialing a telephone number. It was standardized when the dual-tone multi-frequency signaling (DTMF) system was developed in the Bell System in the United States in the 1960s that replaced rotary dialing originally developed in electromechanical switching systems. Because of the installed abundance of rotary dial equipment well into the 1990s, many telephone keypads were also designed to produce loop-disconnect pulses electronically, and some could be optionally switched to produce either DTMF or pulses.
Singtel Optus Pty Limited is an Australian telecommunications company headquartered in Macquarie Park, a suburb in the Northern Sydney region of Sydney, New South Wales, Australia. It is a wholly owned subsidiary of Singaporean telecommunications company Singtel.
A toll-free telephone number or freephone number is a telephone number that is billed for all arriving calls. For the calling party, a call to a toll-free number from a landline is free of charge. A toll-free number is identified by a dialing prefix similar to an area code. The specific service access varies by country.
611 is an abbreviated dialing telephone number in the North American Numbering Plan, implemented by many telephone companies for reporting troubles with telephone service, or with a payphone. It is an N11 code, which are reserved from assignment as area codes or central office codes, for use in special services.
Last-call return, automatic recall, or camp-on, is a telecommunication feature offered by telephony service providers to subscribers to provide the subscriber with the telephone number, and sometimes the time, of the last caller. The service may also offer the facility to place a call to the calling party.
The Australian telephone numbering plan governs the allocation of telephone numbers in Australia. It has changed many times, the most recent major reorganisation by the Australian Communications and Media Authority taking place between 1994 and 1998.
Telephone numbers in Japan consist of an area code, an exchange number, and a subscriber number.
International direct dialing (IDD) or international subscriber dialling (ISD) is placing an international telephone call, dialed directly by a telephone subscriber, rather than by a telephone operator. Subscriber dialing of international calls typically requires an international call prefix to be dialed before the country code.
Telephone number pooling, thousands-block number pooling, or just number pooling, is a method of allocating telephony numbering space of the North American Numbering Plan in the United States. The method allocates telephone numbers in blocks of 1,000 consecutive numbers of a given central office code to telephony service providers. In the United States it replaced the practice of allocating all 10,000 numbers of a central office prefix at a time. Under number pooling, the entire prefix is assigned to a rate center, to be shared among all providers delivering services in that rate center. Number pooling reduced the quantity of unused telephone numbers in markets which have been fragmented between multiple service providers, avoided central office prefix exhaustion in high growth areas, and extended the lifetime of the North American telephone numbering plan without structure changes of telephone numbers. Telephone number pooling was first tested for area code 847 in Illinois in June 1998, and became national policy in a series of Federal Communications Commission (FCC) orders from 2000 to 2003.
Area code 404 is a telephone area code in the North American Numbering Plan (NANP) for Atlanta, Georgia and its closest suburbs. This comprises roughly the area encircled by Interstate 285. It is an enclave area code, surrounded by area code 770, which serves most of Atlanta's suburbs. Both 404 and 770 are overlaid by area codes 678, 470, and 943.
The Mobile Telephone Service (MTS) was a pre-cellular VHF radio system that linked to the Public Switched Telephone Network (PSTN). MTS was the radiotelephone equivalent of land dial phone service.
An intercept message is a telephone recording informing the caller that the call cannot be completed, for any of a number of reasons ranging from local congestion, to disconnection of the destination phone, number dial errors or network trouble along the route.
Area code 246 is the telephone area code in the North American Numbering Plan (NANP) for Barbados. The sequence 246 spells BIM on an alpha-numeric telephone keypad, a nickname for the island.
Area codes 1651 are telephone area codes in the North American Numbering Plan (NANP) for Jamaica.
The New Zealand telephone numbering plan describes the allocation of telephone numbers in New Zealand and the Pitcairn Islands.
In many voice telephone networks, anonymous call rejection (ACR) is a calling feature implemented in software on the network that automatically screens out calls from callers who have blocked their caller ID information.
Telephone numbers in Canada follow the fixed-length format of the North American Numbering Plan (NANP) of a three-digit area code, a three-digit central office code, and a four-digit station or line code. This is represented as NPA NXX XXXX.
A telephone number is a sequence of digits assigned to a landline telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone, or to other devices for data transmission via the public switched telephone network (PSTN), or other public and private networks. Modern smart phones have added a built-in layer of abstraction whereby individuals or businesses are saved into a contacts application and the numbers no longer have to be written down or memorized.
In conventional landline telephony, a non-dialable toll point or toll station was a lone station or line serving a rural subscriber many miles from the nearest central office. As it had no home telephone exchange and therefore no local calling area, no customer could dial its number; all connections to it had to be obtained manually by the long distance operator.
This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on January 22, 2022.
