TryLearn More

Use SIP trunks, WebRTC & Apps

Slash your Phone Bill by 80%

How to Enable Callback on Unsuccessful Blind Transfer in 3CX Phone System

3CX Phone System includes an automatic callback feature in Blind Transfer. If you perform a blind transfer and the recipient of the call is busy, then the call will automatically return back to you. This way you can inform the caller that the person they are trying to contact is busy and proceed to transfer to another destination.

Enabling the Callback Feature

To enable the callback feature, from the 3CX Management Console, go to “General” > “Global Options” tab. Under “System Wide Options”:

callback blind transfer

  1. Configure a unique DialCode to enable this feature. This DialCode must not conflict with other DialCodes that you have configured for your PBX.  For example *3*.
  2. Configure the timeout in seconds that the caller will wait for the destination to answer before the call bounces back. For example 10 seconds.
  3. Click “Apply”.

Using the Callback Feature

When you perform a blind transfer to an extension that is busy, if that extension does become free (hang up) before the configured timeout, then the call will return to the extension that initiated the blind transfer.

When an extension is configured to accept more than one call at the same time (under “Edit Extension” > “Forwarding Rules” > “Available” and “Available 2” tabs), the call will not bounce back, but will instead be handled according to that extensions forwarding rules (by default, if the call is not answered within 20 seconds then the call is sent is sent to voicemail).

If the transferred call is rejected by the recipient it will be directed to his/her voicemail.

Free for up to 1 year! Select preferred deployment:


for Linux on a $200 appliance or as a VM

Get the ISO


for Windows as a VM

Download the setup file

On the cloud

In your Google, Amazon, Azure account

Take the PBX Express