Automatic number identificationwikipedia
Automatic number identification (ANI) is a feature of a telecommunications network for automatically determining the origination telephone number on toll calls for billing purposes.
automatic number identificationANIthe caller's numberautomatic number identification (ANI)

Caller ID

caller IDcaller line identificationCLI
ANI is not related to newer caller ID services such as call display.
The idea of CNID as a service for POTS subscribers originated from automatic number identification (ANI) as a part of toll free number service in the United States.

Toll-free telephone number

toll-free telephone numbertoll-freetoll-free number
Modern toll-free telephone numbers, which generate itemized billing of all calls received instead of relying on the special fixed-rate trunks of the Bell System's original Inward WATS service, depend on ANI to track inbound calls to numbers in special area codes such as +1-800, 888, 877, 866, 855, 844 with 833 and 822 reserved for future toll free use (United States and Canada), 1800 (Australia) or 0800 and 0808 (United Kingdom).
It 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.

Automatic number announcement circuit

automatic number announcement circuitANACautomatic number announcement
ANI is used to provide automatic number announcement, an internal test facility for telephone maintenance workers.
Automatic number announcement systems are based on automatic number identification, and meant for phone company technicians, the ANAC system works with unlisted numbers, numbers with caller ID blocking, and numbers with no outgoing calls allowed.

Long-distance calling

long distancelong-distancelong-distance calling
Automatic number identification was originally created by AT&T Corporation for internal long distance charging purposes, eliminating the need for telephone operators to manually request the number of the calling party for a toll call.
The caller would dial the long-distance operator (typically ‘112’ in large Bell System cities of that era; "0" was for local assistance) and provide the destination city name and called number as well as their own number for billing purposes (there was no automatic number identification).

Telephone number

telephone numberphone numbertelephone numbers
Automatic number identification (ANI) is a feature of a telecommunications network for automatically determining the origination telephone number on toll calls for billing purposes.

Party line (telephony)

party lineparty linestelephone party line
ANI is also not supported properly for calls originated from four-party lines.
Systems which identify the caller's name and address to emergency telephone numbers (such as Enhanced 9-1-1 in North America) may be unable to identify which of multiple parties on a shared line placed a distress call; this is aggravated by the use of old mechanical switching equipment for party lines as this obsolete apparatus consistently provides no caller ID and often also lacks automatic number identification capability.

Dialed Number Identification Service

dialed number identification servicescall tracking
A related service feature available to private branch exchange subscribers is the Dialed Number Identification Service (DNIS), a code indicating the number requested by the caller.

List of CDMA terminology

eHRPDCDMA technology term
ANI – Automatic Number Identification

Machine to machine

M2Mmachine to machinemachine-to-machine
This system, similar but distinct from the panel call indicator of the 1920s and automatic number identification of the 1940s, which communicated telephone numbers to machines, was the predecessor to what is now caller ID, which communicates numbers to people.

Automatic message accounting

automatic message accountingmessage registerscall accounting
In centralized AMA (CAMA), the originating Class 5 telephone switches used automatic number identification (ANI) and multi-frequency (MF) signaling to send the originating and dialed telephone numbers to the Class 4 toll connecting office.

Prank call

prank callprank callsprank phone calls
The advent and advancements in digital switching technologies such as those found in SS7, unspoofable ANI, as well as outbound and inbound calls being logged at carrier exchange equipment, further complicate the pranksters will to remain anonymous while carrying out such activities.

Area codes 905, 289, and 365

905 and 289905289
Automatic number identification (ANI) on the NPA's switching systems began transmission on October 11, 1992 for some central office codes.


PTT ID, or Push-To-Talk ID, is a generic term for an automatic number identification (ANI)-like system used in two-way radio systems.

Enhanced 9-1-1

E911enhanced 9-1-1enhanced 911
These circuits are similar to traditional telephone lines, but are formatted to pass the calling party's number (Automatic Number Identification, ANI).


telephonydigital telephonytelephone
Primary telephone service providers are offering information services such as automatic number identification, which is a telephone service architecture that separates CTI services from call switching and will make it easier to add new services.

Next Generation 9-1-1

next-generation 9-1-1NG 9-1-1
Only minimal data is delivered with these calls, such as automatic number identification, subscriber name and Automatic Location Identification, when available.


NorthwesteltelecommunicationNorthwestel Cable
The wire line facilities along the highway was changed from ring-down services to multi-party lines off dial exchanges as the communities along the line received central office switches, most of which were Ericsson Rurax switches that during the late 1970s were modified to enable direct dialing of long distance calls, though without automatic number identification.

Supervision (telephony)

answer supervisiondisconnect supervisionindicate
Automatic Number Identification (ANI) can also be transmitted.

Telephone exchange

telephone exchangeexchangescentral office
The Bell System dial service implemented a feature called automatic number identification (ANI) which facilitated services like automated billing, toll-free 800-numbers, and 9-1-1 service.

Computer-aided dispatch

computer-assisted dispatchcomputer-aided dispatchcomputer aided dispatch
Computerized mapping, automatic vehicle location, automatic number identification and caller-identification technology are often used to enhance the service by pinpointing the locations of both the client and the most suitable vehicle for serving the client.

Nuisance call

nuisance calltelephone harassmentnuisance calls
Even where end-user Caller ID is not available, calls are still logged, both in billing records at the originating telco and via automatic number identification, so the perpetrator's phone number can still be discovered in many cases.

Panel switch

panel switchpanelPanel system
The introduction of direct distance dialing (DDD) in the 1950s required the addition of automatic number identification equipment for centralized automatic message accounting.

Call box

callboxcall boxcall boxes
The DTMF automatic number identification (ANI) or caller ID from the callbox will be used to display the callbox sign number and its location on the computer-aided dispatch (CAD) system.