Editing Vertical service code

{{Short description|Telephone dialing code for access to service features}}
{{use American English|date=September 2022}}
{{use MDY dates|date=September 2022}}

A '''vertical service code''' ('''VSC''') is a sequence of digits and the signals [[Asterisk|star]] ({{Key press|*}}) and [[Number sign|pound/hash]] ({{Key press|#}}) dialed on a [[telephone keypad]] or [[rotary dial]] to access certain telephone service features.<ref name="NANPA">{{Cite web |title=Vertical Service Codes – Code Definitions |url=https://nationalnanpa.com/number_resource_info/vsc_definitions.html |publisher=North American Numbering Plan Administrator |website=NationalNANPA.com |access-date=2022-07-30 }}</ref> Some vertical service codes require dialing of a [[telephone number]] after the code sequence. On a [[touch tone]] telephone, the codes are usually initiated with the [[Asterisk#Telephony|star key]], resulting in the commonly used name ''star codes''. On rotary dial telephones, the star is replaced by dialing ''11''.

In [[North American]] [[telephony]], VSCs were developed by the [[American Telephone and Telegraph Company]] (AT&T) as '''Custom Local Area Signaling Services''' ('''CLASS''' or '''LASS''') codes in the 1960s and 70s. Their use became ubiquitous throughout the 1990s and eventually became a recognized standard. As ''CLASS'' was an AT&T trademark, the term ''vertical service code'' was adopted by the [[North American Numbering Plan Administration]]. The use of ''vertical'' is a somewhat dated reference to older switching methods and the fact that these services can only be accessed by a telephone subscriber, going up (''vertically'') inside the local [[telephone exchange|central office]] instead of out (''horizontally'') to another telephone company.

==Feature definitions==
The following are the vertical service codes generally recommended by the [[North American Numbering Plan Administrator]] for use in the NANP territories. Not all of these services are available in all areas, and some are only available on [[landline]] telephones or [[Mobile phone]]s.

Local Area Signalling Services (LASS) and Custom Calling Feature Control Codes:<ref name="NANPA" /><ref>{{Cite magazine |title=The #Hack FAQ|url=http://www.phrack.com/issues.html?issue=47&id=7 |author=voyager |editor=Erik Bloodaxe |magazine=Phrack Magazine |page=7 |date=1995-04-15 |access-date=2013-03-18 }}</ref><ref>{{Cite web |title=Vertical Service Codes – Code Assignments |url=http://www.nanpa.com/number_resource_info/vsc_assignments.html |publisher=Neustar |work=NANPA.com |access-date=2013-03-18 }}</ref>

{| class="wikitable sortable"
|-
! colspan="2" | Vertical service code
! rowspan="2" | Service definition
! rowspan="2" | Australia
! rowspan="2" | Japan
! rowspan="2" | UK
|-
! Tone<br>dialing
! Pulse<br>dialing
|-
| align="center" | *51
| align="center" | 1151
| ''Who called me''. Provides the directory number, date and time of unanswered calls.
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *52
| align="center" | 1152
| Call Hold (Single Line Variety Package). Permits the call to be picked up at another station.
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *53
| align="center" | 1153
| Distinctive Ring B. Allows a subscriber to alert a specific party distinctively.
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *54
| align="center" | 1154
| Distinctive Ring C. Allows a subscriber to alert a specific party distinctively.
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *57
| align="center" | 1157
| [[Call trace]] (Malicious caller identification)
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *60
| align="center" | 1160
| [[Call blocking]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *61
| align="center" | 1161
| [[Priority call]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *62
| align="center" | 1162
| Selective call waiting
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *63
| align="center" | 1163
| Selective [[call forwarding]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *65
| align="center" | 1165
| [[Caller ID|Calling number]] delivery activation
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *66
| align="center" | 1166
| [[Continuous redial]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *67
| align="center" | 1167
| Calling number delivery blocking
| align="center" | 1831<br>#31#<ref>1831 on landlines, or #31# from a mobile</ref><ref>{{cite web|title=HOW TO: block your number when calling someone|url=https://exchange.telstra.com.au/how-to-block-your-number-when-calling-someone/|website=Telstra Exchange|publisher=Telstra|access-date=28 May 2017}}</ref>
| align="center" | 
| align="center" | 141<br>#31#<ref>141 on landlines and #31# on mobiles</ref>
|-
| align="center" | *68
| align="center" | 1168
| Activate call forwarding on busy
| align="center" | 
| align="center" | 
| align="center" | 
|- 	 
| align="center" | *69
| align="center" | 1169
| [[Last-call return]] (incoming)
| align="center" | *69 HFC<br> *10#<ref>*10# for [[Telstra]] services [http://www.telstra.com.au/homephone/features_services/call_return.html "Telstra Home Phones and Plans – Call Return"] {{webarchive|url=https://web.archive.org/web/20110314000130/http://www.telstra.com.au/homephone/features_services/call_return.html |date=March 14, 2011 }}</ref><ref> *69 on [[Optus]] HFC Telephony network. [http://personal.optus.com.au/web/ocaportal.portal?_nfpb=true&_pageLabel=Template_wRHS&FP=/personal/customerhelp/producthelp/homephonehelp/homephonehowtoguides/usingcallreturn&site=personal "Optus Personal – Using Call Return"] This only allows one to return the last unanswered call, and can cost 35 cents per use.</ref>
| align="center" | 1361<br>1363<ref>1361 to get number, 1363 to call back. {{cite web |url=http://www.ntt-east.co.jp/release/0007/000717b.html |title=NewsRelease |website=NTT East |access-date=June 20, 2013}} {{cite web |url=http://www.ntt-west.co.jp/denwa/service/136/gaiyou.html |title=Number OSIRASE 136 |website=NTT West |access-date=June 20, 2013}}</ref>
| align="center" | 1471<ref>After dialing 1471, the caller can press "3" to automatically return the call. Previously free, since August 2004 the return call service incurs a charge.</ref>
|-
| align="center" | *70
| align="center" | 1170
| [[Call waiting]] disable
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *71
| align="center" | 1171
| Usage sensitive three-way call
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *72
| align="center" | 1172
| [[Call forwarding|Unconditional forward: All calls]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *73
| align="center" | 1173
| [[Call forwarding|Call forward: Cancel]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *74
| align="center" | 1174
| [[Speed calling]] (8 numbers)
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *75
| align="center" | 1175
| [[Speed calling]] (30 numbers)
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *77
| align="center" | 1177
| [[Anonymous call rejection]] activation
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *78
| align="center" | 1178
| Do not disturb
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *79
| align="center" | 1179
| Do not disturb disable
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *80
| align="center" | 1180
| [[Call blocking|Call blocking disable]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *81
| align="center" | 1181
| [[Priority call]] disable
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *82
| align="center" | 1182
| [[*82|Caller ID (per call)]]
| align="center" | *31#/1832<ref>1832 on landlines, or *31# from a mobile</ref>
| align="center" | 
| align="center" | 1470
|-
| align="center" | *83
| align="center" | 1183
| Selective call forwarding disable
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *85
| align="center" | 1185
| [[Caller ID|Caller ID disable]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *86
| align="center" | 1186
| [[Continuous redial|Continuous redial cancel]]
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *87
| align="center" | 1187
| [[Anonymous call rejection]] deactivation
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *88
| align="center" | 1188
| Deactivate call forwarding on busy
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *89
| align="center" | 1189
| [[Last-call return]] cancel
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *90
| align="center" | 1190
| Conditional forward: Busy line
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *92
| align="center" | 1192
| Conditional forward: No answer
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *94
| align="center" | 1194
| Directed call pickup
| align="center" | 
| align="center" | 
| align="center" | 
|-
| align="center" | *272
| align="center" | 
| [[Nationwide Wireless Priority Service|Wireless Priority Service]]
| align="center" | 
| align="center" | 
| align="center" | 
|}

== See also ==
{{Portal|Telephones}}
* {{Annotated link|Mobile dial code}}
* [[Pat Fleet]] – Prompt voice for most U.S. [[AT&T Corp.|AT&T]] implementations of VSC features
* {{Annotated link|Public switched telephone network}}
* {{Annotated link|Short code}}

==References==
{{Reflist}}

==External links==
* [http://portal.etsi.org/HF/hf_service_codes.asp ETSI Supplementary service codes]

{{FS1037C}}

[[Category:Calling features]]
[[Category:North American Numbering Plan]]
[[Category:Telephone numbers in Canada]]