Next time you need to see your iPhone’s IMEI number, you don’t need to look far away. All you need to do is press *#06# and press the call key. iPhone will then return the device’s IMEI number.
By pressing *43# and pressing call, you activate a mode called Call Waiting. When this mode is activated, iPhone will notify the user if a second call is coming while you are on the first call. This mode even allows users to choose to always answer incoming calls later.
To turn off Call Waiting mode, you can press code #43# and press call.
Not showing your phone number when making calls
A good trick to help you make a phone call but the other side cannot see your phone number displayed is to press *#31# before the phone number to call and press call. Imagine how useful this feature would be in case you were calling a store about an item that just saw an advertisement on the Internet but didn’t want them to have your number as an example.
Block incoming calls
iPhone allows users to transfer all incoming calls to voicemail mode by pressing *#21#. This is clearly a great way for you to enjoy the day to the fullest or to focus on doing something. Just remember to turn it off when you are ready to return by pressing *#21# and press call!