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Q: Telephone Service ( Answered 4 out of 5 stars,   1 Comment )
Subject: Telephone Service
Category: Miscellaneous
Asked by: gollum9701-ga
List Price: $20.00
Posted: 24 Dec 2005 07:10 PST
Expires: 23 Jan 2006 07:10 PST
Question ID: 609467
I believe that if a person dials *67 before dialing the number that he
or she wishes to call, it blocks the receiving party from seeing the
caller's phone number.

Is there an exception or loophole whereby the receiving party could
learn the caller's number (other than by a police related governmental

If the receiving party has an "800 type number (including 866 and
877)" can he or she see the caller's number?

If the receiving party dials *57 to connect to the last party that
called him or her, would he be provided with the caller's number?
Subject: Re: Telephone Service
Answered By: webadept-ga on 24 Dec 2005 07:56 PST
Rated:4 out of 5 stars

Caller ID and Automatic Number Identification (ANI) are two seperate
things. If the number you are calling is setup to recieve ANI then
there is no way for you to block this.

For Caller ID to work, the two parties must be on digital exchanges,
that are linked by SS7. Many calling card companies are not SS7
connected, and different routing can mean that calls between the same
two numbers may or may not show the Caller ID. Caller ID is not
possible from most analogue mobile phones.

*67 Caller ID Per Call Blocking - allows a subscriber to block
delivery of his/her name and number when calling someone with Caller
ID capabilities. The activation code for this feature is (*67)
push-button or 1167 rotary. This feature is provided free of charge to
all subscribers receiving telephone service from suitably equipped
central offices.

So according to the above, depending on the receiving telephone
service, and the standard they are using for this call, you may or may
not be able to effectivly block your Caller ID using *67. If the
receiver is setup to use ANI, then blocking is impossible.

"*57 Call Trace - allows a subscriber to have the last incoming number
automatically traced. The results of the trace are not provided
directly to the subscriber; they are outputted to the Telephone
Company. The Company, at the subscribers request, will forward the
results to the police after a case number has been assigned by the
police. The access code for this feature is (*57) push-button or 1157
The quoted areas are from

A very good FAQ on Digital Caller ID and other information can be found here:
Caller ID FAQ


Request for Answer Clarification by gollum9701-ga on 24 Dec 2005 16:36 PST
Is ATC widely available and used by large numbers of businesses
(and/or individuals)? I never heard of it before.
gollum9701-ga rated this answer:4 out of 5 stars
Quite informative.

Subject: Re: Telephone Service
From: markvmd-ga on 24 Dec 2005 13:59 PST
Toll-free numbers CAN display your caller ID info. The logic with the
phone folks is the person paying for the call has the right to see who
is calling. You cannot assume that star-67 is blocking the caller ID
when calling a toll-free number.

This is what Webadept is saying here---> "If the number you are
calling is setup to recieve ANI then there is no way for you to block
this." Many of the toll-free folks have ANI.

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