You need to know that all codes below are safe and cannot harm you devices in anyway, they are only useful for certain purposes and they are all safe.
General device status
When you dial this particular code it displays the device’s information, battery, wifi information and many other interesting usage statistics.
Viewing IMEI number
The International Mobile Equipment Identity (IMEI) number is a number that’s unique in every devices, it is just like serial number that identifies your device. Among other things, it can add on the “blacklist” a stolen device so that it will not be reused. At the same time, it can help when you need customer care help.
Checking call forwarding
This code let you know whether call forwarding is enabled when you are another call, it can even let you know if the provider’s voicemail service is activated.
Just dial the below code on your dial pad, that’s all.
How to disable caller ID in outgoing calls
Dialing this code makes your number to be invisible to your call receivers, any number you call will not be able to see your phone number, which means they won’t be able to call you back nor send you message on the number you used to call them.
dial #31# before the number they wish to call to disable it.
How to enabling caller ID in outgoing calls
This is just the opposite of the above code, and it is as simple as pressing four keys on your phones, but these four keys are indeed a useful one. Someone else might press the above code and disable your caller ID you should just press this below one and enable the caller ID again.
This code is *31#.
Enabling call waiting on your sim
Take note that this code fork for your sim not for phone, which means when you put your sim in another phone the code will still be functioning.
This code here enable new calls to show on your phone despite the fact that you on another call, it enable you to know who wants to talk to you while on another call instead of rejecting the call and tell them you are busy. Just dial the below code
Disabling call waiting
Just the opposite of the above code, but I will not advise you to use it, because disabling it will make you not to know who had called when you are on another call, well if you still need the code it is here.
Checking call blocking
When you dial this called it will let you know if you have blocked incoming call or not.
Checking GPS functionality
When you dial this code, it shows the corresponding screen.
Checking firmware version
This code works mostly on Samsung’s Galaxy devices, while it may not work on other smartphones.
This is one of the most drastic secret codes, as it will delete everything, just like formatting your phone where you will have another firmware installed.
You must know this action is irreversible and all data on your device will be formatted, if you still need the code, here it is.
No one knows it all, so any one can do something on the phone and they will want to reset the phone to the factory settings, even me myself, I have used this cold several times, so this code might be the last solution when you mis-set something on your phone
There are still many codes useful in phone apart from the ones in this article, if there is one particularly that you need let us know from the comment section, thank you for reading.