Call diversion depends on the network operator and usually forwards missed calls to the mobile or mailbox.

If you wish, we can enter a personal telephone number for call forwarding, or deactivate the service altogether.

The following call forwarding settings are available in the phone app of the OnePlus smartphone:

Android 10 | OxygenOS 10.0
Step 1:  Open the  Phone app
Step 2:  Open the  menu
Step 3:  Open the  Settings
Step 4:  Tap on  Calling accounts
Step 5:  Choose a  SIM card   (Dual SIM)
Step 6:  Tap on  Call forwarding
Step 7:  Choose an  option
Step 8:  Update the  phone number  or tap on  Turn off  to disable call forwarding
  1. Open the Phone app
  2. Open the menu
  3. Open the Settings
  4. Tap on Calling accounts
  5. Choose a SIM card (Dual SIM)
  6. Tap on Call forwarding
  7. Choose an option
  8. Update the phone number or tap on Turn off to disable call forwarding

OnePlus Instructions