Call forwarding

Call forwarding (or call diverting), in telephony, is a feature on some telephone networks that allows an incoming call to a called party, which would be otherwise unavailable, to be redirected to a mobile telephone or other telephone number where the desired called party is situated. Usually (though not always)the forwarded line rings once, to remind the customer using Call forwarding that the call is being redirected.

How to Use

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 NANP generally uses the following vertical service codes to control call forwarding:

Forward service	Activation	Deactivation	Number change
All calls	*72	*73
On busy or no answer	*68	*88
From select callers	*63	*83
On ISDN			*56
Customer-programmable features (where available):
Busy line	*90	*91	*40
No answer	*92	*93	*42

For wireless phones, GSM standard defines the following forward codes:

Forward service	Activate	Cancel & Deregister	Cancel & Retain	Status	Reestablish
Unconditional forwarding:
All Calls	*21*[phone number]#	##21#	#21#	*#21#	*21#
Conditional forwarding:
If Busy	*67*[phone number]#	##67#	#67#	*#67#	*67#
If Not Answered	*61*[phone number]#	##61#	#61#	*#61#	*61#
If Out of Reach	*62*[phone number]#	##62#	#62#	*#62#	*62#
Simultaneous forwarding:
All Forwards	*002*[phone number]#	##002#	#002#	*#002#	*002#
All Conditional Forwards	*004*[phone number]#	##004#	#004#	*#004#	*004#

Some carriers use *71 for conditional forwarding despite the fact that this is not to standards.

When and Why to Use it

Diverting calls can increase one's availability to a caller. In addition, some people do not wish to leave a message, and many people delay returning their messages. Sometimes, to deactivate a call forwarding, *720 will work on cellphones.

Some businesses find that the human touch can improve levels of sales, and they have their clients' calls forwarded to a call center, so the client can reach an operator instead of an answering machine or voice mail.