Do you have a prankster or an ex who keeps dialing your number and you want to block that phone number?
Worry no more!
Based on your phone model and your carrier there are definite ways to block a phone number. Let us find out how to block a phone number by making use of some of the easiest services and with the help of technology as well.
How to Block a Phone Number from calling you?
Following methods explain how to block a phone number and one of these methods WILL work for your particular case.
National Do Not Call Registry
If you want to block pestering telemarketers from calling you, then the way to go is the National Do Not Call Registry. Once you register yourself at the DNC Registry then you will stop receiving call from telemarketing call centers and even if you receive a one-off call, you may take legal steps and compensated for the same. Please note that DNC takes up to a month to activate your registration.
Carrier Assistance to Block a Phone Number
In the US, some phone carriers offer paid ways to block phone numbers, AT&T being the leader at that.
AT&T Wireless: A&T Smart Controls offer a service called Parental Controls that can be used to limit the incoming and outgoing numbers (i.e. who can call you or whom you can call). Though, it is meant for parental controls, it works well for blocking a prankster.
Other carriers: If your carrier is Sprint, T-Mobile or Verizon, unfortunately there is no service like the one AT&T provides. However, you could always use the Caller ID feature and a good Call blocker Caller ID device 
(Note: Please check with your Carrier once before investing on a call blocking device. Some of the carriers have started offering limited options to block five or ten selected numbers)
How to Block a Phone Number on Your Specific Phone Model?
Android Phones: If you have an Android phone, then you can Download the FREE Call Blocker application for your phone to get freedom from all unwanted calls. This is an extremely good and user friendly android app.
iPhone: If you are an iPhone user there’re paid applications that you can use to block unwanted calls. You may search the iTunes market place for a suitable app or use something like MCleaner that works like a charm.
Blackberry: How to block a phone number on Blackberry? Well, there are good call blocker app on BlackBerry as well. The one I have seen working good on my friend’s phone is the Call Blocker Professional.
Windows Mobile Phones: There are a number of phone blocker apps for Windows Mobile that you can dig out by searching. I do not have a particular application to suggest for the time being but I have seen many.
Nokia: If you own a Nokia smart phone, you may use the BlackList or Best BlackList app to block unwanted numbres.
Most phone manufactures have started realizing the need to have options within the phone itself to block certain numbers. Some of them have options to redirect calls to voicemail if the incoming call is not from a created list. Check your phone options for any such features.
Services like YouMail
Free web services like YouMail can be used to block unwanted voice calls to your mobile phone. Check your phone’s compatibility with such services before going for the same.
Good luck for taming your phone pest or prankster! And if you know any other method to block a phone number, please share your tip as comments here.