World Library  
Flag as Inappropriate
Email this Article

Directory assistance

Article Id: WHEBN0000449894
Reproduction Date:

Title: Directory assistance  
Author: World Heritage Encyclopedia
Language: English
Subject: Telegate, Telephone number, List of North American Numbering Plan area codes, 118 118 (Sweden), Infone
Collection: Directory Assistance Services, Telecommunication Services
Publisher: World Heritage Encyclopedia

Directory assistance

In telecommunications, directory assistance or directory enquiries is a phone service used to find out a specific telephone number and/or address of a residence, business, or government entity.


  • Technology 1
    • Directory assistance data sources 1.1
  • North America 2
    • Rate classes 2.1
    • Toll-free directory assistance 2.2
    • Companies specializing in free directory assistance 2.3
  • United Kingdom 3
    • Pricing 3.1
    • Charities 3.2
  • China 4
  • Ethiopia 5
  • Israel 6
  • See also 7
  • References 8
  • References 9
  • External links 10


Directory assistance systems incorporate a wide range of automation to reduce the cost of human operators. Almost all systems use custom database software to locate listings quickly.

Most directory assistance systems use automated readback systems to give out the phone number. This frees the directory assistance operator to move on to another caller as soon as the correct listing is located.

Some systems have "store and forward" technology which records "city and state" the caller is requesting and then plays the city and state speech to the operator before they come online and then say "Residential or business listing?" or simply "What listing please?"

Interactive voice response systems have been added to many directory assistance systems. These complex systems use speech recognition and recorded speech or speech synthesis to handle the entire call without live operator intervention.

Most systems recognize location and listing. If recognition confidence is high, the best result is played to the caller. If confidence is low, the caller's request is played back to a live operator, who locates the correct listing.

Directory assistance data sources

The services of 4-1-1 queries is often outsourced to a call centre who specializes in that function. Historically, when a single carrier provided most of the telephony services for a region, the data used to satisfy the search could exclusively come for that carriers subscriber rolls. Today, when the market is fragmented amongst many carriers, the data must be aggregated by a data aggregator specializing in directory listings, such as LSSi. The data aggregator distributes the data to the 4-1-1 services either on a "live" basis, actually servicing each query, or by periodically transferring large swaths of listings to the call center's systems for local searching or for online directory assistance searching at 411 directory assistance.

The data aggregator collects the data from the rolls of many telecommunication carriers. Some carriers such as Vonage do not send their customer rolls to the aggregator. Their customers can get their listings in the directory assistance database using a free service such as

North America

In the North American Numbering Plan (covering Canada and the United States), directory assistance may be contacted by dialing 4-1-1 (one of the N11 codes) or to get a listing in a remote or non-local area code, directory assistance is available at 1-area code-555-1212 or online at 411 Directory Assistance[1]

However, a 411 landline call will provide local listings as well as nationwide listings and sometimes international listings.

Most telephone companies permit up to two listings per 411 call. All wireless carriers offer nationwide listings with 411, and some offer additional Enhanced Directory Assistance services.

Rate classes

U.S. wireline telephone companies classify DA into four rate classes.

  1. 411 LDA — Local Directory Assistance. 411 is dialled and the operator is requested to search for a listing in a group of area codes "LATA" local to the caller. Example: the caller lives in area code 630 (Oak Brook, IL) and request a listing for a business in area code 312 (Chicago, IL). In this case, AT&T Illinois bills the call.
  2. 411 NDA — National Directory Assistance. 411 is dialled and the operator is requested to search for a listing in an area code not local to the caller. Example: The caller lives in area code 630 (Oak Brook, IL) and requests a listing for a business in area code 213 (Los Angeles, CA). In this case AT&T Illinois bills the call.
  3. (area code) 555-1212 — National Directory Assistance. This example assumes the caller is in Oak Brook, IL (area code 630) and uses MCI as their long distance carrier. Example: The caller is looking for a listing in Los Angeles, CA (area code 213) and dials 213-555-1212. In this case MCI bills the call.
  4. 00 and ask for the international directory assistance operator. AT&T provides International Directory Assistance calls. See for additional information and country and city codes.

Toll-free directory assistance

In the U.S., directory assistance for companies with toll-free "800 numbers" (with area codes 800, 844, 855, 866, 877, and 888) is available from toll-free directory assistance.

Toll-free directory assistance is provided by AT&T as mandated by the Federal Communications Commission. Companies must request to have their toll-free number listed and pay AT&T each time their phone number is released to a Toll-free directory assistance caller. AT&T had applied for discontinuing this service[2] but it remains active.

Companies specializing in free directory assistance

Recently private companies have entered the directory assistance market by offering free directory assistance. Customers often must listen to an advertisement prior to receiving directory services.[3]

United Kingdom

The BT foreign directory assistance centre in Grimsby (1996).

In the United Kingdom, directory assistance is called directory enquiries. The service is provided by a variety of different companies, with a variety of call charges, each company reached by dialling a six digit number beginning 118. These companies supply information from the Operator Services Information System (OSIS), which is run by Directory Solutions, a division of BT Wholesale. OSIS accepts updates from telecoms providers seven days a week, and supplies that information to the enquiry companies six days a week.[4] There are currently over 200 providers. Three of these, 118 500 (BT), 118 888 (Conduit) and 118 118 (The Number), have over 90% of the market, mostly due to heavy advertising.

Directory enquiries used to be reached by dialling 192 (domestic numbers) or 153 (foreign), with the service supplied by the telephone company providing the fixed or mobile service to the calling telephone. These numbers were switched off on 24 August 2003 following the introduction of competition to directory enquiries.

A number offering a directory enquiries service allowing people to request to be put through to a mobile phone number was established in June 2009.[5] 118 800 proved to be controversial, however, when it was revealed that it was making available 15 million mobile numbers that it had bought from market researchers.[6] Its website was suspended[7] within weeks of its launch so that the company could re-engineer the site to enable the large number of ex-directory requests to be handled more efficiently.[6] As of 2014 the site remains non-functional.

Viral emails regarding 118800 are generally thought to be responsible for the deluge of unsubscribe requests. The virals spread panic by alleging that the 118800 service was about to give out phone numbers which would be available to marketers. The 118800 service have maintained that these emails are without substance referring enquirers to their website where the service is explained.[8] 118800 do not, at any time, release telephone numbers to callers but rather send a message to the mobile phone owner letting them know that the enquirer wishes to be connected to them. The recipient of the call retains the right to accept or refuse the call but either way the caller is never notified of the mobile phone number being contacted.


The pricing structure for UK directory enquiries is very complex. Some services are fixed fee, some are per minute and some are a combination of the two. Each number is allocated to a code from dq1 to dq153 and these are shown in BT's pricing table section 2, part 15[9] Having found the "dq" code, it is then necessary to refer to part 19 to find the cost.[10]


Some services donate part of their income to charities, such as animal welfare and football clubs.[11]


In mainland China, (area code) 114 is dialed for directory assistance in that area code.[12]


In Ethiopia, 8123 is dialed for directory assistance. The service can also be accessed through the site Afalagi's website


In Israel, 144 or 1344 is dialed for directory assistance. The service can also be accessed online through Bezeq's website

See also


  1. ^ 411 Directory Assistance 411 Directory Assistance
  2. ^ * 
  3. ^ Bernstein, Fred A. (9 March 2006). "The 411 on Directory Assistance". The New York Times. Retrieved 1 May 2010. 
  4. ^ "BT Wholesale Directory Solutions - About Us".  
  5. ^ "118 800 To Connect UK To Millions Of Mobile Numbers". Real Wire. 9 June 2009. Retrieved 19 July 2009. 
  6. ^ a b Osborne, Hilary (13 July 2009). "Mobile phone directory suspended". London: The Guardian. Retrieved 14 July 2009. 
  7. ^ "'"118800 Mobile Enquiry Service Temporarily Suspended. PR Log. 29 July 2009. 
  8. ^ "The Only Directory with Millions of Mobile Numbers". 15 June 2009. Retrieved 15 July 2009. 
  9. ^
  10. ^
  11. ^
  12. ^ "号码百事通". China Telecom. Retrieved 14 July 2013. 


External links

  • Mark Lawson, The Guardian, 19 March 2005, "Dial 0 for progress"
  • Patrick Hosking, New Statesman, 6 September 2004, "The business - Patrick Hosking wonders if 999 will be privatised"
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.