f-bd356d62-013e-43d4-8cfc-02ea1e36deb2

f-4a8a5595-783b-4e0e-8467-d2d5e9fc4016

Apple iPhone 16 Pro Max

iOS 18

I can't make voice calls on my Apple iPhone 16 Pro Max iOS 18

Cause 1 of 3: Missed calls are diverted too fast

Your missed calls are diverted after a specified number of seconds. If your calls are diverted too fast, you need to select a longer period of time.

Solution: Set divert delay.

Step 1 of 8

Find "Keypad"

Press the phone icon.

Step 2 of 8

Find "Keypad"

Press Keypad.

**21*121#

**21*121#

**21*121#

Step 3 of 8

Divert all calls

Key in **21*121# and press the call icon.

**61*121*20#

**61*121*20#

**61*121*20#

Step 4 of 8

Divert missed calls

Key in **61*121*20# and press the call icon.

**62*121#

**62*121#

**62*121#

Step 5 of 8

Divert if unavailable

Key in **62*121# and press the call icon.

**67*121#

**67*121#

**67*121#

Step 6 of 8

Divert if busy

Key in **67*121# and press the call icon.

Step 7 of 8

End call

Press Dismiss.

Step 8 of 8

Return to the home screen

Slide your finger upwards starting from the bottom of the screen to return to the home screen.

1 Find "Keypad"

Press the phone icon.

Press Keypad.

2 Divert all calls

Key in **21*121# and press the call icon.

**21*121#

3 Divert missed calls

Key in **61*121*20# and press the call icon.

Key in the required number of seconds before the call is diverted, e.g. 20. The number needs to be divisible by 5.

**61*121*20#

4 Divert if unavailable

Key in **62*121# and press the call icon.

**62*121#

5 Divert if busy

Key in **67*121# and press the call icon.

**67*121#

6 End call

Press Dismiss.

7 Return to the home screen

Slide your finger upwards starting from the bottom of the screen to return to the home screen.