An emergency telephone number is a number that allows a caller to contact local emergency services for assistance. The emergency number differs from country to country; it is typically a three-digit number so that it can be easily remembered and dialed quickly. Some countries have a different emergency number for each of the different emergency services; these often differ only by the last digit.
A blue box is an electronic device that produces tones used to generate the in-band signaling tones formerly used within the North American long-distance telephone network to send line status and called number information over voice circuits. During that period, charges associated with long-distance calling were commonplace and could be significant, depending on the time, duration and destination of the call. A blue box device allowed for circumventing these charges by enabling an illicit user, referred to as a "phreaker" to place long-distance calls, without using the network's user facilities, that would be billed to another number or dismissed entirely by the telecom company's billing system as an incomplete call. A number of similar "color boxes" were also created to control other aspects of the phone network.
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.
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.
A Zenith number was a telephone service in the United States that allowed a calling party to call the service subscriber at no charge by requesting the name Zenith and the number from a switchboard operator. The service preceded the system of toll-free telephone numbers with area code 800 in the United States. Some areas used the names "Enterprise" or "WX" number.
A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, reachable by a system of destination code routing. Telephone numbering plans are defined in each of the administrative regions of the public switched telephone network (PSTN) and in private telephone networks.
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.
The area code 868 is assigned to Trinidad and Tobago, a member of the North American Numbering Plan (NANP). The telephone numbering plan for the country is known as the National Numbering Plan. It is part of a system used for assigning telephone numbers in Trinidad and Tobago, and functions as a part of the North American Numbering Plan (NANP). It is regulated by the Telecommunications Authority of Trinidad and Tobago, which holds responsibility for telecommunications in the country.
A telephone exchange name or central office name was a distinguishing and memorable name assigned to a central office. It identified the switching system to which a telephone was connected, and facilitated the connection of telephone calls between switching systems in different localities.
Numbers on the Irish telephone numbering plan are regulated and assigned to operators by ComReg.
Telephone numbers in Singapore, also known as the National Numbering Plan, are regulated by the Info-communications Media Development Authority (IMDA). Due to the small geographical size of Singapore, there are no area or trunk codes; all numbers belong to one numbering area, and thus come in the same 8-digit format. Numbers are categorised based on the first digit, thus providing ten possible categories, of which six are currently in use and the remaining four reserved for future usage.
The dialling plan for mobile networks and new landline operators is closed; all subscriber numbers must be dialled in full. For landline numbers starting with 02, the dialling plan used to be open; the trunk digit and area code could be omitted if the caller was in the same area code as the callee. However, starting May 3, 2008, all landline numbers must be dialled in full.
The New Zealand telephone numbering plan describes the allocation of telephone numbers in New Zealand and the Pitcairn Islands.
The area code 671 is the local telephone area code of the United States territory of Guam. It was created with the beginning of permissive dialing on July 1, 1997, replacing Guam's previous International Telecommunication Union country code 671 at the end of permissive dialing on July 1, 1998.
National conventions for writing telephone numbers vary by country. The International Telecommunication Union (ITU) publishes a recommendation entitled Notation for national and international telephone numbers, e-mail addresses and Web addresses. Recommendation E.123 specifies the format of telephone numbers assigned to telephones and similar communication endpoints in national telephone numbering plans.
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.
Ranges for fictitious telephone numbers are common in most telephone numbering plans. One of the main reasons these ranges exist is to avoid accidentally using real phone numbers in movies and television programs because of viewers frequently calling the numbers used. In North America, the area served by the North American Numbering Plan (NANP) system of area codes, fictitious telephone numbers are usually of the form (XXX) 555-xxxx. The use of 555 numbers in fiction, however, led a desire to assign some of them in the real world, and some of them are no longer suitable for use in fiction. Other areas have different fictitious telephone numbers.
A misdialed call or wrong number is a telephone call or text message to an incorrect telephone number. This may occur because the number has been physically misdialed, the number is simply incorrect, or because the area code or ownership of the number has changed. In North America, toll-free numbers are a frequent source of wrong numbers because they often have a history of prior ownership. In the United Kingdom, many misdialed calls have been due to public confusion over the dialing codes for some areas.
Toll-free telephone numbers in the North American Numbering Plan have the area code prefix 800, 833, 844, 855, 866, 877, and 888. Additionally, area codes 822, 880 through 887, and 889 are reserved for toll-free use in the future. 811 is excluded because it is a special dialing code in the group NXX for various other purposes.
