trace private callers

This is one of the most common questions on Y! answers... "how can I trace the last call who called me with there number blocked?" or some variation of this question...

the answer is, with a land line telephone you can not unmask the caller ID information... at least not directly...

what you can do is block private callers by activating ACR... to do this just dial *77 you will hear an announcement that the ACR service is active.. if you ever wish to disable this feature in the future and get calls from private numbers you just need to dial *87. When this feature is activated callers with private numbers will need to dial *82 before calling you to unblock there number on a per-call basis.

you can place a trace on the last call that came in by dialing *57, I have a blog entery that explains this in better detail, so read that entry if you wish to learn more about this feature..

for cell phones, there is a new service called trap call that will unmask private callers telephone numbers, this service will also work to defeat people who call with spoofed caller ID information. what you need to do is go to http://trapcall.com and sign up for the service, and set your phone up to forward rejected calls to trapcall's toll free number. once the call is rejected it goes to trapcalls toll free number, and then the call is rerouted back to you with the ANI information displayed for the caller ID information. this is why it is useful in unmasking private callers, and spoofed caller id.

to use trapcall from your landline, you would need to forward ALL of your landline calls to the cell phone that you set trapcall up on... you may not want to do this on a normal basis, and it may be difficul to know when someone is going to call you with a private number that you want unmasked, but if you have been getting harassing calls in the middle of the night, you can forward your calls to your cell at night (most cell plans have free nights and weekends anyhow) so the call will forward to your cell, and you will be able to activate trapcall on the private caller...

EDIT - Trapcall no longer offers a free service, all levels of service are now paid.