It depends on your carrier, but yes, you can. Not from your phone: you will probably have to call your service provider and have an operator/CSR block the number manually. But it is definitely possible.
For cell phones call from the cell phone 888-3821222
Type "*67" before the number.
To block a number on 'at' - you have to call your credit number, and you credit number should give you some options. It should say, and for anything else please press (for example) 4. Press this, then press 5. And it will ask you if you want to unlock your phone, or block a number. Press 2 to block a number, then click options, keypad, type in number, then you click phonebook, and click the number you want to block. Then give your details to pay £5 Or $7 to block a number. :] Hope This Helps!
YOu can get the app Mr. Number
Depends on what cell phone it is.
Call customer service or see if there is an instruction manual for your phone.
You call your servize provider and tell them to block that number that you want blocked
Some cell phone companies may not allow voices messages to be left when a number has been blocked, while other cell phone companies will allow a voice message.
To block a number, simply dial *60, then press the hash key. Once you hear the dial tone, type in the number that you wish to block, followed by the hash key. This will block the number.
some land line phone companies allow you to block all private or unknown numbers......If you can check your account from your computer you can do it that way or call your phone company. As far as cell phones Im unsure.
You can change your number or let your phone company know about it and they should be able to block that number from contacting you.
You do this in account setting within Yahoo the best is to remove cell number completely