Directory assistance

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

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.


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.

North America[edit]

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). To get a listing in a remote or non-local area code, directory assistance is available at 1-area code-555-1212. In some cases, a 411 call from a landline will yield local, national, 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. However, wireless numbers for residential customers are not available via 411.


Historically, the tariffs for wireline telephone service allowed subscribers to place a certain number of directory assistance calls for free each month. More recently, telephone companies are charging subscribers for every directory assistance call.

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 local to the caller (LATA). Example: the caller lives in area code 630 (Oak Brook, IL) and requests 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 Verizon 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 Verizon 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[edit]

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 telecommunication providers, namely AT&T and Verizon, as mandated by the Federal Communications Commission. Companies must request to have their toll-free number listed and pay the providers each time their phone number is released to a Toll-free directory assistance caller. In 1999, AT&T applied for permission to discontinue this service[1] but it remains active.

Directory assistance data sources[edit]

The service of 4-1-1 queries is often outsourced to a call centre that 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 come exclusively from that carrier's subscriber rolls. Today, when the market is fragmented amongst many carriers, the data must be aggregated by a data aggregator specializing in directory listings. 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.

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.

Companies specializing in free directory assistance[edit]

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.[2]


Directory assistance is available from Telstra by calling 1223 for domestic numbers or 1225 for international numbers.

United Kingdom[edit]

The BT foreign directory assistance centre in Grimsby (1996)

In the United Kingdom, directory assistance is called directory enquiries.

Directory enquires is provided by a variety of different companies, with a variety of call charges, each company reached by dialling a six-digit number beginning with 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.[3] There are currently over 200 providers.[4] Four of these, 118 118 (The Number), 118 212 (Maureen), 118 247 (Yellow Pages) and 118 500 (British Telecom) are among the most expensive and yet have over 90% of the market, mostly due to heavy advertising.[citation needed]

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. Historically the service was free at the point of use. During the 1990s charges were brought in to use this service from home or business lines, although for some years after directory enquiries were free from payphones. These numbers were switched off on 24 August 2003 following the introduction of competition to directory enquiries.


The pricing structure for UK directory enquiries was reformed by Ofcom on 1 July 2015.[5] Call charges consist of an access charge and a service charge. The access charge is set and retained by the caller's landline or mobile provider. The service charge is set by the directory enquiries service but it is collected by the caller's phone provider and then passed on to the directory enquiries service.

The access charge is set at a per minute rate and is typically 2p to 13p per minute from landlines or 5p to 55p per minute from mobiles. The access charge is always the same rate as applies for calls to 084, 087 and 09 numbers and must be shown prominently in tariff lists.

The service charge may be charged per call, per minute, or a combination of the two. The per-call part may be anywhere from 5p to £16 and applies as soon as the call is answered. The per-minute part may be anywhere from 1p to £8 and may apply from the start of the call or may apply after the first 60 seconds has elapsed. There are 100 available service charge price points, known as SC001 to SC100.[6][7] The service charge must be declared alongside the number wherever it is advertised or promoted.[8]

The applicable service charge codes are also shown in BT's pricing table section 2, part 15.[9] Having found the "SC" code for a particular number, it is then necessary to refer to part 19 to find the cost.[10]


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.[11] 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.[12] Its website was suspended[13] 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.[12] As of 2017 the site remains non-functional.

In 2014, the 118500 service run by BT was fined £225,000 by PhonepayPlus (now renamed as the Phone-paid Services Authority) for over-charging customers and failing to clearly display call costs.[14] BT were also ordered to refund affected customers.

Later in 2014, a similar failure to clearly state call costs resulted in a fine for the 118118 service.[15][16]

In 2017, soaring call costs for directory enquiries services including 118118 and 118500[17] prompted an Ofcom review of 118 services.[18][19][20]

Some directory enquiries services stand accused of inappropriate methods of promoting their services, effectively scamming people into calling. Various unallocated geographic and non-geographic numbers play an announcement directing callers to call a particular directory enquiries number for help. People may hear this message when they mis-dial a wanted number[21] or may appear to have missed a call from the unallocated number and hear this message if they call back.


Some services donate part of their income to charities, such as animal welfare and football clubs.[22]


In mainland China, (area code) 114 is dialed for directory assistance in that area code.[23]


In Ethiopia, 8123 is dialed for directory assistance.


In Israel, 144 or 1344 is dialed for directory assistance.


In the Philippines, 187 is dialed for PLDT[24] and Digitel subscribers.


In Taiwan, directory assistance is available by dialing 105 from mobile phones, or by dialing 104 from landline phones.

See also[edit]


  1. ^ *AT&T Inc. (16 November 1999). "Discontinuance - AT&T Toll-Free Directory Assistance Service - 1-800-555-1212". FCC Public Notices. Federal Communications Commission. Retrieved 2007-12-28.
  2. ^ Bernstein, Fred A. (9 March 2006). "The 411 on Directory Assistance". The New York Times. Retrieved 1 May 2010.
  3. ^ "BT Wholesale Directory Solutions - About Us". British Telecom. Archived from the original on 2009-11-30. Retrieved 13 January 2010.
  4. ^ "Directory Enquiry Codes". Magenta Systems. 2017-05-03. Archived from the original on 2017-05-06.
  5. ^ "UK Calling". Ofcom. 2014-09-16. Archived from the original on 2017-04-03.
  6. ^ "UK NGN Call Charges SC001 to SC100". Uboss. 2016-07-01. Archived from the original on 2016-06-09.
  7. ^ "Subpart 6: Calls to Service Numbers (numbers starting 084, 087, 09 and 118) from 1 July 2016". Section 2:Call Charges & Exchange Line Services - Part 1: Basic Inland Call Charge. BT. 2016-07-01. Archived from the original on 2017-01-30.
  8. ^ "How does UK Calling affect businesses?". Ofcom. 2014-09-16. Archived from the original on 2017-04-04.
  9. ^ "BT Price List – Section 2, Part 15". Retrieved 2016-06-07.
  10. ^ "BT Price List – Part 19: Calls to Directory Enquiry 118 Services". Retrieved 2016-06-07.
  11. ^ "118 800 To Connect UK to Millions of Mobile Numbers". Real Wire. 9 June 2009. Archived from the original on 2009-06-12. Retrieved 19 July 2009.
  12. ^ a b Osborne, Hilary (13 July 2009). "Mobile phone directory suspended". London: The Guardian. Archived from the original on 2013-09-06. Retrieved 14 July 2009.
  13. ^ "118800 Mobile Enquiry Service Temporarily Suspended". PR Log. 29 July 2009. Archived from the original on 2012-08-30.
  14. ^ Rickard Straus, Rachel; Poulter, Sean (2014-02-04). "Does BT owe you a refund? Callers to £2.39 a minute directory enquiries can get their money back after telecoms giant is fined". Daily Mail. Archived from the original on 2014-04-02.
  15. ^ Goodman, Rob (2014-04-03). "118 118 fined £80,000 for misleading adverts". Moneywise. Archived from the original on 2014-04-06.
  16. ^ Jones, Rupert (2014-04-03). "118 118 fined for lack of clarity over pricing". The Guardian. Archived from the original on 2014-04-06.
  17. ^ Jones, Daniel (2017-05-07). "DIABOLI-CALL - Calls to directory enquiries more expensive than sex lines as greedy firms fleece OAPs with sneaky hikes leaving calls costing up to £9". The Sun. Archived from the original on 2017-05-10.
  18. ^ "Telephone review to ensure value for callers". Ofcom. 2017-05-12. Archived from the original on 2017-05-12.
  19. ^ "Ofcom opens investigation into the cost of 118 calls". BBC News. 2017-05-12. Archived from the original on 2017-05-12.
  20. ^ Stubbs, Georgina (12 May 2017). "Ofcom to probe rising costs of 070 and 118 calls". Daily Mail. Press Association. Archived from the original on 13 May 2017.
  21. ^ Jones, Daniel (2017-05-11). "New 118 Scam Exposed - Pensioner hit with £111 bill after being tricked into calling a premium 118 number". The Sun. Archived from the original on 2017-05-11.
  22. ^ "118 Numbers - 118donate". Ethcom. Archived from the original on 2015-07-17. Retrieved 2016-06-07.
  23. ^ "号码百事通" (in Chinese). China Telecom. Retrieved 14 July 2013.
  24. ^ "Contact Us". Retrieved 2016-06-07.

External links[edit]