Editing Call forwarding (section)

==Keypad codes==
===North America===
Special types of call forwarding can be activated only if the line is busy, or if there is no answer, or even only for calls from selected numbers.  In [[North America]], the [[North American Numbering Plan]] (NANP) generally uses the following [[vertical service code]]s to control call forwarding:

{| class="wikitable"
!Forward service!!Activation!!Deactivation!!Number change
|-
|All calls || align="center" | *72<br>*72[1+e number] (some larger cities)

| align="center" | *73 ||
|-
|On busy or no answer ||align=center| *68 || align="center" | *81<br />||
|-ad
|From select callers ||align=center| *63 ||align=center| *81 ||
|-
|On [[ISDN]] || || ||align=center| *56
|-
| colspan="4"| Customer-programmable features (where available):
|-
|Busy line  ||align=center| *90 ||align=center| *91 ||align=center| *41
|-
|No answer ||align=center| *92 ||align=center| *93 ||align=center| *611
|}

The [[Sprint Nextel]] cellphone company uses these:<ref name="sprint120749">{{cite web|url=http://support.sprint.com/support/article/Find_out_more_about_call_forwarding/case-vw371511-20091020-120749 |title=Find out more about call forwarding |work=Support and Services |publisher=Sprint.com |access-date=2010-05-22 |url-status=dead |archive-url=https://web.archive.org/web/20100204103406/http://support.sprint.com/support/article/Find_out_more_about_call_forwarding/case-vw371511-20091020-120749 |archive-date=February 4, 2010 }}</ref>

{| class="wikitable sortable"
|+
!Forward service!!Activation!!Deactivation
|-
|On busy or no answer ||align=center| *28[phone number] ||align=center| *38
|-
|On busy              ||align=center| *74[phone number] ||align=center| *740
|-
|On no answer         ||align=center| *73[phone number] ||align=center| *730
|-
|Immediately          ||align=center| *724704732775 || align="center" | *720
|-
|}

* {{as of|2012|01}}, Sprint charges 20 cents per minute for unconditional call forwarding; conditional call forwarding is included, however.<ref name="sprint387303">{{cite web | url=http://community.sprint.com/baw/message/387303 | title=iPhone 4S/Call Forwarding | work=Support and Services | publisher=Sprint.com | date=2012-01-17 | access-date=2012-06-24}}</ref>
* Some carriers (including Verizon Wireless) use *71 for conditional forwarding although this is not standard.<ref name="verizon">{{cite web | url=http://support.verizonwireless.com/clc/features/calling_features/no_answer_transfer.html | title=Calling features: No Answer/Busy Transfer | work=Support | publisher=Verizon Wireless | access-date=2012-06-24 | archive-date=2012-06-20 | archive-url=https://web.archive.org/web/20120620033352/http://support.verizonwireless.com/clc/features/calling_features/no_answer_transfer.html | url-status=dead }}</ref>
* Sometimes, to deactivate call forwarding, *720 will work on cellphones.{{citation needed |date=December 2021}}

===Europe===
Most EU fixed-line carriers use the following codes based on [[European Conference of Postal and Telecommunications Administrations|CEPT]] and [[European Telecommunications Standards Institute|ETSI]] standards developed in the 1970s on both [[Plain old telephone service|POTS]] and [[ISDN]] lines. (There may be some variation to these, but the unconditional code *21* is very much universally standard on EU telephone lines.) The general syntax for all European service codes always follows the pattern below:

{| class="wikitable"
|+Unconditional forwarding
!Forward service!!Activate!!Cancel & Retain!!Reestablish!!Status
|-
|If busy || align="center" | *69*[phone number]# or<br>*67*[phone number]# || align="center" | #69# or #67# || align="center" | *69# or *67#|| align="center" | *#69# or *#67# 
|-
|If not answered || align="center" | *61*[phone number]# || align="center" | #61# || align="center" | *61#|| align="center" | *#61# 
|}

===Mobile (cell) phones===
For GSM/3GSM (UMTS) phones, the [[Global System for Mobile Communications|GSM]] standard defines the following forwarding [[Unstructured Supplementary Service Data]]. These were developed by ETSI and are based on standard European diversion codes and are similar to those used on most landlines in the EU:<ref name="geckobeach">{{cite web | url=http://geckobeach.com/cellular/secrets/gsmcodes.php | title=GSM feature codes | work=Tips and Secrets | publisher=Gecko Beach | access-date=2010-07-26}}</ref>

{| class="wikitable"
!Forward service!!width:100px|Activate!!width:150px|Cancel & Deregister!!width:150px|Cancel & Retain!!width:100px|Status!!width:100px|Reestablish
|-
!colspan="6" style="background:#FFFFCC;"| Unconditional forwarding
|-
|All calls ||align=center| *21*[phone number]# ||align=center| ##21# ||align=center| #21# ||align=center| *#21# ||align=center| *21#
|-
!colspan="6" style="background:#FFFFCC;"| Conditional forwarding
|-
|If busy ||align=center| *67*[phone number]# ||align=center| ##67# ||align=center| #67# ||align=center| *#67# ||align=center| *67#
|-
|If not answered (see below for custom delay)||align=center| *61*[phone number]# ||align=center| ##61# ||align=center| #61#
|align=center| *#61#<br>(incl. time delay)
|align=center| *61#
|-
|If out of reach ||align=center| *62*[phone number]# ||align=center| ##62# ||align=center| #62# ||align=center| *#62# ||align=center| *62#
|-
|All forwards ||align=center| *002*[phone number]# ||align=center| ##002# ||align=center| #002# ||align=center| *#002# ||align=center| *002#
|-
|All conditional forwards ||align=center| *004*[phone number]# ||align=center| ##004# ||align=center| #004# ||align=center| *#004# ||align=center| *004#
|}

If the prefix to the forwarding command is "**" (instead of the usual "*"), then the phone number in that command is registered in the network. If after that the forwarding is deactivated using a command with a single "#", then later it will be possible to re-activate this forwarding again with a simple "*" command without a phone number in it. The forwarding will be re-activated to the number registered in the network. For example, if one uses the out-of-reach code in a forwarding command:

<code>**62*7035551212#</code>

and after that one deactivates the forwarding:

<code>#62#</code>

then later it will be possible to re-activate the out-of-reach forwarding without specifying a number:

<code>*62#</code>

After the above command, all calls made to the phone, while it is out of reach, will be forwarded to 7035551212. It is possible to activate the feature to a number other than the registered number, while still retaining the registered number for later use. For example, issuing the command:

<code>*62*7185551212#</code>

will result in calls being forwarded to 7185551212 (and '''not''' to the ''registered number'' 7035551212). However, if later a command is issued:

<code>*62#</code>

then the calls will again be forwarded to the registered number 7035551212 (and '''not''' to the number from the previous forwarding command 7185551212).

===Forwarding delay===
In GSM networks of some US carriers, and in all mobile networks in Europe, it is possible to set a number of seconds for the phone to ring before forwarding the call. This is specified by inserting "''*SC*XX''" prior to the final "#" of the forwarding command, where "''SC''" is a ''service type code'' (11 for ''voice'', 25 for ''data'', 13 for ''fax''), and "''XX''" is the number of seconds in increments of 5 seconds. If "''SC''" is omitted (just "''**XX''") then by default ''all service types'' will be forwarded. For example, forwarding on no-answer can be set with:

<code>*61*[phone number]**[seconds]#</code>

Forwarding voice calls only can be set with:

<code>*61*[phone number]*11*[seconds]#</code>

In some networks there may be a limit of not more than thirty seconds before forwarding (i.e. “''XX''” can only be 05, 10, 15, 20, 25, or 30; all greater values, like 45 and 60, will result in the forwarding command being rejected and an error message returned).