Call Forwarding is a feature available on most smart phones that redirects a telephone call to another destination.
You can enable “Call Forwarding” by following the general guides for either Android or iOS devices. Please note that steps may differ slightly depending on the Android phone model / iOS version.
Android:
Find and tap Phone.
Tap the menu button (three vertical dots), then tap Settings.
Tap Calls/Supplementary Services
On the Call settings page, tap Call forwarding. You now have several options, and can choose the one that best suits your needs.
iPhone:
Start the Settings app.
Tap "Phone."
Tap "Call Forwarding."
Turn on Call Forwarding by swiping the button to the right.
Tap "Forward To."
Enter the phone number that you want to redirect your phone calls to.
When you're done, use the back button to save your changes.
Note: Airtime charges will apply for calls being forwarded as it is treated as an outgoing call.