To block caller ID for an individual call, dial 1831 (or #31# from a mobile) then the number you are calling. Generally, this will make sure the person you are calling will not see your number.
If you want to hide the caller ID dial *31# and press call button. This code allows you to check which number your phone is currently forwarding calls to when you're busy or reject a call. If you want to deactivate call waiting dial #43#.
10. *31# (Disable Caller ID) If you want to keep your privacy and prevent others from knowing when you call them, you can disable caller ID by using this code. If you want to re-enable caller ID, just add the code again.
To block CND on all calls from your phone, contact your telco. To block caller ID for an individual call, dial 1831 (or #31# from a mobile) then the number you are calling. Generally, this will make sure the person you are calling will not see your number. If you have problems with caller ID, complain to your telco.
Hide Your Phone From Caller ID: #31#
I could only get this to work on Android. But entering this code prompted a pop-up stating that my Caller ID had been disabled. In order to re-instate Caller ID, enter *31# .
Step 1: On the Home Screen, tap Phone. Step 2: Press the left menu button and tap Call settings. Step 3: Under Call settings, tap Additional settings. Step 4: Under additional settings, tap Caller ID.
Dial *69
Dialing *69 is a convenient way to call back the last private number that called you. If a caller has blocked their number from being displayed on your caller ID, dialing *69 can unmask the private number, allowing you to call it back.
Open the dialing pad as if you were making a phone call. Type *#0*#. The menu will appear automatically.
By pressing *3370# or #3370#, you'll activate your phone's “reserve battery power”.
The *#9900# code is a diagnostic mode code for Samsung mobile devices. It can be used to access a variety of system information and diagnostic tools, such as enabling/disabling fast dormancy, logging options, and system dump mode.
Call “##004#”
This number is an internationally recognised code. No one will answer when you call it, but it will turn off conditional forwarding on your phone. It will reset your phone to its default phone settings.
*57 is a call tracing service offered by most phone companies. It allows you to easily trace calls made to your phone number. Essentially, *57 records the calling number and other identifying information such as the date and time of the call.
*67 - Caller ID Block: Hides your phone number on Caller ID systems. *69 - Call Return: Redials the last number that called you. *70 - Call Waiting: Places your call on hold so you can answer another. *72 - Call Forwarding: Forward your call to another phone number.
You can use *67 or #31# before dialing the number, or you can have your carrier permanently block your number from appearing. If you're using an Android or iPhone, you can also change the settings in your phone.
Immediately after a missed call from an unknown number or a number that shows up as No Caller ID, dial *69. From here, you will be able to trace the number—and name and address if listed in a public database—to reveal the number and possibly more information about the identity of the strange number that's calling you.
*66: Busy Call Return
The Busy Call Return service allows you to call a busy line over and over automatically for 30 minutes.
How to Use *67 on an Android or iPhone. You can prevent your number from appearing on a recipient's phone or caller ID device when you place a call using a smartphone or a traditional landline by pressing *67 followed by the number you want to call.
To block your mobile phone number on a per-call basis, dial #31# before each phone number you call. To permanently block your number use your Call Settings menu. Get step-by-step instructions for your device on how to hide your caller information.
You can activate one-time blocking of Outbound Calling Name Display by dialing #31# before the number of the person you're calling, followed by pressing either the Send or Talk key. You can also set up the blocking on some phones via their menu.