When someone chooses to block a phone number, people may know that the phone number is blocked, depending on the type of blocking involved. When people configure a number for blocking, they can usually choose from several options which may either conceal the blocking, or indicate that the number is being blocked. Call blocking can be used on both incoming and outgoing calls, allowing people to remain anonymous when they call out and to avoid calls from specific individuals, or to only accept calls from certain people.
In the case of blocking for outgoing calls, there are two ways to block a phone number. One method involves paying the phone company to block the number, and the other involves selective blocking, in which someone presses *67 before making a call to block the number. If the person being called does not have caller identification, she or he will have no way of knowing that the number is blocked. If the person does have caller identification, the incoming call will show up as “unknown,” “private number,” or “blocked,” allowing the call recipient to see that the number has been blocked or that it cannot be identified.
When it comes to blocking inbound calls, a phone subscriber can ask the phone company to selectively block calls from specific numbers, which allows phone subscribers to block a phone number which belongs to a particular person or group, or use a phone screening device which blocks all calls which are made without a special code.
If calls are blocked by the phone company, when someone dials the number, he or she will hear a busy signal or a message which indicates that the subscriber is not accepting calls from the caller's number. If someone opts to block a phone number in this way, callers will only know that they are being blocked if they hear the recorded message. If a screening device is used at home, a recorded message will play indicating that someone needs to enter a special code to successfully reach the person being called, in which case a caller will obviously realize that his or her number is blocked.
The drawback to using a blocking device at home is that it blocks calls from everyone who does not have the code. This means that people may miss calls they actually want to receive from people or organizations who do not have the code, including emergency services. For this reason, choosing selective blocking of specific numbers through the phone company is recommended, unless someone has been a victim of telephone harassment, thinks that taking steps to block a phone number belonging to a specific person would not be enough, and would prefer to limit incoming calls to a specific group of individuals such as family and friends.