Press the menu button on your phone, then go to "Settings."  Go to "Phone" or "Phone Settings" and select "Calls" or "Incoming Calls."  Press "Blocked Callers," "Blacklist," "Unwanted Calls," or another similarly named option menu.  Your contact list or phone book will appear; choose the name you wish to block, or manually enter the phone number you wish to block.  Hit "OK" or "Block" to confirm. Calls from this number will no longer appear and will not cause your cell phone to ring.  The caller will either hear a busy signal or will be informed that you do not accept calls from his or her number. This is a free app that is available from your phone's Play Store and provides the option of blocking both anonymous and specific numbers.  Go to your Play Store and search for "Call Filter."  Download the app and then open it.  Once open, you will have the option of checking a box that reads "Block Unknown Calls."  This will prevent private numbers, pay phones, and unknown numbers from contacting you.  You can also check a box next to "Control Specified Numbers," which will block numbers you have manually entered.  Beneath the box is a gray, clickable icon that says "Call Filter" with a number in parentheses.  Click this box to input numbers to be blocked.  The number of blocked callers will now show in this gray box. Similarly, you can click "Add the last incoming number" to block the most recent number that has called you. Call blocking apps are not 100% effective and may still allow telemarketers to call you. If you do not have an Android phone, similar apps are available which offer nearly identical features. Google Voice is a free phone service that offers a wide range of features.  Visit the sign-up website: https://services.google.com/fb/forms/googlevoiceinvite/.  You will be prompted to enter your name and e-mail address.  Since this service is through invitation only, you will be required to wait until Google Voice has sent you an invite before utilizing account features.  Be patient; the site advertises a "short" wait but can take up to a few days to process.  Follow the e-mail instructions for signing up for an account. Once you have created an account, log in to your Google Voice account.  Find a call or voicemail from the caller whom you want to block and select a check box next to that call or voicemail.  Click the "More" link underneath the call/voicemail.  Select "Block Caller."  This feature works on all phones as it is linked to a Google account and not a specific phone.
किसी खास नंबर को ब्लॉक करें: अपने एंड्रॉयड पर कॉल फ़िल्टर एप (Call Filter) को डाउनलोड करें: गूगल वॉइस से कॉल ब्लॉक करें: