How to Trace Blocked Cell Phone Numbers

By Lori Spencer

If you want to find out who's been calling you from a blocked, anonymous or private number, it's not always an easy thing to do. Generally, you cannot trace the number unless the calls are obscene, harassing or threatening, in which case, you should alert your cell phone service provider and the local authorities. There are, however, some steps you can take to document cases of harassing calls from private numbers. You also can pay for private services, which will investigate the source of anonymous calls.

Step 1

Document every call you receive from a blocked or private number. You can do this by accessing your cell phone's "incoming/missed calls" or Caller ID on your land-line phone.

Step 2

Keep a written log noting the date and time of each incoming blocked call. This will be important in civil or criminal investigations.

Step 3

Contact your phone company and ask them if they can identify who is behind the "private" or "anonymous" number (this is not always possible).

Step 4

Ask your phone company to block all calls from the number that keeps harassing you. This will work only if your phone company can positively identify the number.

Step 5

Hire a private investigator if the anonymous calls are really bothering you. Be prepared to spend up to several hundred dollars if your harasser isn't easy to locate.

Step 6

Unblock private numbers with TrapCall. As of August 2010, TrapCall is the only company that offers this service to the general public; such technology was previously only available to police and private investigators.

Step 7

Go to and select one of the service plans. As of 2010, the monthly fee is around $25. However, TrapCall does offer a free 15-day trial.

Step 8

Follow TrapCall's setup guide to forward unwanted blocked calls to TrapCall's toll-free number. Callers will never know their call is being forwarded; they will simply hear your standard voice mail greeting if you do not accept the call.

Step 9

Sit back and let the TrapCall service work it's magic: the call will be re-routed back to you, this time with the caller ID unblocked. Then add the troublesome number to your "blocked callers" list.

Tips & Warnings

  • TrapCall's paid service offers additional features including voice mail transcription, incoming call recording, the name and billing address of parties calling you and more.
  • Once you know the number that's calling, you should contact your phone service provider directly and ask the provider to block all incoming calls from that specific number. (Some companies may charge a nominal fee to do this.)
  • While the unmasking of blocked calls is helpful to people frustrated with annoying telemarketers and prank callers, there are privacy concerns about services such as TrapCall. Victims of domestic violence or stalking use caller ID blocking (*67) as a form of protection.
  • If you are receiving repeated harassing, threatening or obscene calls from a blocked number, contact your local police immediately. Authorities can trace the number and find out who's calling. They will not release this information to you; it will be available only to investigators.