No name comes up on my caller ID

People making calls to your number can use a few different ways to make sure that their name and number does not appear on a caller ID. They can choose to block a number on a per call basis or they can choose to block the entire line. Per-call blocking can be done by dialing *67 before the destination number is dialed. If the entire line is blocked dialing *82 before a call will unblock the number.

When a caller uses one of these codes before dialing a mobile phone, in many instances, the receiver's phone will prompted them to "accept" or "withhold" the call. This simply allows the person receiving the call to drop it (hang up) without answering it.

There are also some phone companies that offer a service to counter blocked numbers. This is often referred to as "Anonymous Call Rejection". The service programs your phone to immediately reject any call that has its number blocked. There is also a "Block the Blocker" service lets a caller hear an announcement letting them know the person they are trying to reach doesn't accept calls from numbers that are blocked.

There are also a number of devices on the market that mirror this same effect. The benefit of using one of these is they eliminate the monthly service charge you will otherwise pay your phone company.

How long does it take for a number to get displayed?

- If I dial and hang up quickly, would the person still who the call came from?

Caller ID devices needs at least one ring to identify the number. So, if the person you are calling has caller ID, then yes, they will know where the call came from. Now, if they do not have caller ID, in most circumstances, they will still be able to dial *69, and the telephone company will provide them with the number which called them. If they so chose, that number can be used to search for your name using a reverse phone lookup (see our article on reverse phone lookups for more). Either of these methods will allow them to see it was you that called even though you hung up after just the first ring.

Now for finding out who is behind the number…and dealing with it.

There are two different ways to deal with an unknown number. The easiest way may be to use a phone number "trace". To perform a trace you must dial *57 directly following the call. This activates the call trace with your phone provider. The line will be followed even if the call was made from a "blocked" number. Once you do this, the number is then reported to the phone company (not to you). Please note, you will likely be required to pay a fee to use this service.

If you have a log of the calls from your caller ID you may also be able to contact your phone company and determine if the blocked calls originated from the same number (again, the number will likely not be given to you, just confirmation if it was the same caller). Sometimes, the phone company will need to set up a "trap" to help determine this. Traps allow the phone company to determine where the calls are coming from the next time you are phoned from that number.

These are two ways in which you may use your phone company to uncover the owner of the blocked number. Unfortunately, the phone company is unlikely to provide you with this information. These services are intended to provide information to law enforcement, which brings us back to our first point. If you really want to stop these calls you may need to talk to your phone company about blocking them to begin with.