Cisco IP Phone

[Daniov1]

Hi ,
My customer wants to have the following:
When client hold "#" on IP Phone pad the Phone automatically place a call to some number(without press "dial" just hold the button "#" for a few seconds).

Thanks.

[Leo Laohoo]

It is called "speed dial".
Why hold the "#" key? Client only wants one number? What happens if the client wants more than one number?

[Daniov1]

The client want to hold "#" for emergency calls.
There is translation pattern configured on CUCM for "#" pattern which translate "#" to the Emergency number.
The client doesn't use "#" button for something else. 

[George Sotiropoulos]

As Leo described below, you should consider creating a Speed-Dial, what type of Phone Device does your costumer use?

[Jaime Valencia]

That cannot be done, if they're on hook, you need to press dial to place a call, just leaving a button pressed does nothing. If they're off hook, the translation pattern will do the job.