What&#x27;s known as &quot;caller ID&quot; is just an add-on that phone companies glued onto the system to have a feature to sell to the public. Another such feature is ANI[1] which was originally meant for billing purposes but is a feature sold with toll-free (800) numbers. It is much harder to spoof, but even ANI is not guaranteed to be present.<p>I would really love to hear a telecom engineer explain why the true origin info isn&#x27;t accessible to the called person. A telephone call is a two-way connection -- the path in both directions <i>must</i> be known otherwise you won&#x27;t have a two-way conversation.<p>A telephone call is not email or an old-fashioned letter. Both of those are one-way communications, so if the intermediaries don&#x27;t carefully track the email or letter as it progresses through the pipeline, you have spoofed email or untraceable letters.<p>But at the lowest level of the telephony protocol, the true and correct path to the originating caller <i>has to</i> exist. Otherwise your voice won&#x27;t travel to the other person. I&#x27;m curious to know why that really deep reverse route has never been made available to public (as an API or a purchasable feature or in any other form).<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Automatic_number_identification" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Automatic_number_identificatio...</a>