Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Automatic number identification
open-in-new
<h2 id="toll-free-telephone-numbers">Toll-free telephone numbers</h2> <p>Modern <a href="/facts/Toll-free_telephone_number/n9cLQxlh">toll-free telephone numbers</a>, which generate itemized billing of all calls received instead of relying on the special fixed-rate trunks of the <a href="/facts/Bell_System/GspEoeEF">Bell System</a>'s original <a href="/facts/Wide_Area_Telephone_Service/UzdwWm35">Inward WATS</a> service, depend on ANI to track inbound calls to numbers in special <a href="/facts/Area_code/jaryReDv">area codes</a> such as +1-800, 888, 877, 866, 855, 844, and 833 with 822 reserved for future toll free use (United States and Canada), 1800 (Australia) or 0800 and 0808 (United Kingdom). </p> <h2 id="privacy">Privacy</h2> <p>ANI is conceptually and technically different from caller ID service.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> A caller's telephone number and line type are captured by ANI service even if <a href="/facts/Caller_ID/hh9DqEEj">caller ID blocking</a> is activated. The destination telephone company switching office can relay the originating telephone number to ANI delivery services subscribers. Toll-free subscribers and large companies normally have access to ANI, either instantly via installed equipment, or from a monthly billing statement. Residential subscribers can obtain access to ANI information through third party companies that charge for the service.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> </p><p>ANI is generally not transmitted when a call is operator assisted; only the area code of the last switch to route the call is sent. </p> <h2 id="automatic-number-announcement">Automatic number announcement</h2> <p>ANI is used to provide <a href="/facts/Automatic_number_announcement_circuit/Lg3pWU3U">automatic number announcement</a>, a test facility of a central office for telephone installation technicians. The service, which is not advertised to the public, allows an installer to identify a line by dialing a telephone number. Such numbers are typically assigned in a <a href="/facts/Plant_test_number/4t2G3PeM">a range reserved for testing purposes</a> (such as 958-xxxx in much of North America). </p> <h2 id="dnis">DNIS</h2> <p><a href="/facts/Dialed_Number_Identification_Service/EQ1a3NE4">Dialed Number Identification Service</a> (DNIS) is a related service feature available to <a href="/facts/Private_branch_exchange/eLWvlhzs">private branch exchange</a> subscribers.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a><a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> It transmits information about the destination number, which a service provider can use to have several toll-free numbers directed to the same <a href="/facts/Call_center/jxKon6G8">call center</a> and provide unique service. DNIS can also be used to identify other call routing information. For example, toll-free service can be configured to send a specific DNIS number that is assigned to callers from geographic regions based on city, area code, state, or country. </p> <h2 id="similar-services">Similar services</h2> <ul><li>Europe: <a href="/facts/Calling_Line_Identification/hh9DqEEj">Calling Line Identification</a> (CLI)</li> <li><a href="/facts/United_Kingdom/kuPAILt2">United Kingdom</a>: <a href="/facts/Caller_Line_Identification/hh9DqEEj">Caller Line Identification</a> (CLID)</li> <li><a href="/facts/Australia/qLHpbppq">Australia</a>: Automatic number identification (ANI) 1800801920 or 12722123 (Telstra line only, local call cost)</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Anthony Ramirez (April 4, 1992). "Caller ID: Consumer's Friend or Foe?". The New York Times. Retrieved September 21, 2022. <a href="https://www.nytimes.com/1992/04/04/news/caller-id-consumer-s-friend-or-foe.html" target="_blank">https://www.nytimes.com/1992/04/04/news/caller-id-consumer-s-friend-or-foe.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"The Pizza Version of Dialing '911'". The New York Times. September 9, 1991. <a href="https://www.nytimes.com/1991/09/09/business/the-pizza-version-of-dialing-911.html" target="_blank">https://www.nytimes.com/1991/09/09/business/the-pizza-version-of-dialing-911.html</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>US Patent 2,265,844: Calling Line Identification Circuit <a href="http://www.freepatentsonline.com/2265844.html" target="_blank">http://www.freepatentsonline.com/2265844.html</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>US Patent 2,300,829: Calling Line Identification System <a href="http://www.freepatentsonline.com/2300829.html" target="_blank">http://www.freepatentsonline.com/2300829.html</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>"ANI II Digits". North American Numbering Plan Administration. 2003. Archived from the original on June 18, 2007. Retrieved July 6, 2007. <a href="http://www.nanpa.com/number_resource_info/ani_ii_assignments.html" target="_blank">http://www.nanpa.com/number_resource_info/ani_ii_assignments.html</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Anthony Ramirez (April 4, 1992). "Caller ID: Consumer's Friend or Foe?". The New York Times. Retrieved September 21, 2022. <a href="https://www.nytimes.com/1992/04/04/news/caller-id-consumer-s-friend-or-foe.html" target="_blank">https://www.nytimes.com/1992/04/04/news/caller-id-consumer-s-friend-or-foe.html</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Fallon, Sean (February 17, 2009). "TrapCall Displays Blocked Numbers on Your Caller ID". Gizmodo. Retrieved June 26, 2021. <a href="https://gizmodo.com/5155206/trapcall-displays-blocked-numbers-on-your-caller-id" target="_blank">https://gizmodo.com/5155206/trapcall-displays-blocked-numbers-on-your-caller-id</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Encyclopedia of Information Technology. Atlantic Publishers and Distributors LTD. 2007. p. 142. ISBN 978-81-269-0752-6. <a href="978-81-269-0752-6" target="_blank">978-81-269-0752-6</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>>Waite, Andrew. A Practical Guide to Call Center Technology. p315. >Waite, Archived 2014-06-28 at the Wayback Machine <a href="https://books.google.com/books?id=pyguvxndiogC&pg=PA315&lpg=PA315&dq=at%26t+dnis&source=bl&ots=dRVcDwKkRz&sig=Wk3_lj9i68Ur63tUpk_Np28uM94&hl=en&ei=rSAKS8_jNdKWtge20ryzCg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CA8Q6AEwAjge#v=onepage&q=at%26t%20dnis&f=false" target="_blank">https://books.google.com/books?id=pyguvxndiogC&pg=PA315&lpg=PA315&dq=at%26t+dnis&source=bl&ots=dRVcDwKkRz&sig=Wk3_lj9i68Ur63tUpk_Np28uM94&hl=en&ei=rSAKS8_jNdKWtge20ryzCg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CA8Q6AEwAjge#v=onepage&q=at%26t%20dnis&f=false</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> </ol>