How to Block Calls to Your Cellphone from Unknown Phone Numbers

You can go through your phone company, use third-party services, or find apps that allow you to block unwanted calls to your cell phone.


Up next in How to Make the Most of Your Cellphone (28 videos)

Make the most of your cellphone with these Howcast videos, which teach you how to send a ringtone to your phone; get pictures from a phone to a computer; block calls from unknown phone numbers; send pictures from a computer to a cellphone; track a cellphone; send pictures to Facebook from a cellphone; get Twitter on your phone; and much more.

You Will Need

  • Phone company custom calling services
  • Phone company privacy manager
  • Inbound call blocker
  • Smartphone call blocker apps
  • National Do Not Call Registry account


  1. Step 1

    Use phone company custom calling services

    Use phone company custom calling services. Program your phone to block calls from specific numbers, or block calls from the last person who called you.

  2. Call Return is a phone company custom service that allows you to call back callers with unknown numbers.

  3. Step 2

    Use a privacy manager service

    Use a privacy manager service offered by many phone companies. A privacy manager service requires anonymous callers to identify themselves in order to complete the call.

  4. Step 3

    Consider an inbound call blocker product

    Consider an inbound call blocker product that only allows callers to ring through by entering a numeric code through their touch-tone keys.

  5. The downside of inbound call blockers is that many can block calls from emergency services or other important unexpected callers.

  6. Step 4

    Use call blocking phone apps

    Use call blocking applications available for specific smartphone models, including Android and Blackberry. Be aware, though, that not all models offer call blocking apps.

  7. Step 5

    Register with the Do Not Call Registry

    Register your phone number online with the Federal Trade Commission's National Do Not Call Registry. The National Do Not Call Registry is an effective method to block unwanted spam calls.

  8. In 1995, a prankster called Buckingham Palace, impersonated Canadian Prime Minister Jean Chretien, and talked to the queen for 17 minutes.