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Phones and the AI receptionist

Caller ID spoofing

spoofing / showing a different number / is caller ID spoofing legal / number substitution

In short

Caller ID spoofing is sending a number other than the line you are calling from. The federal prohibition is not about the technique. It applies to transmitting misleading or inaccurate caller identification information with the intent to defraud, cause harm, or wrongfully obtain anything of value.

The clause everybody skips is the one that decides the answer. The statute makes it unlawful to knowingly transmit misleading or inaccurate caller identification information. Then it adds the condition: with the intent to defraud, cause harm, or wrongfully obtain anything of value. The rule that implements it puts that condition first, before the act it prohibits.

So the prohibited thing is not the substitution. It is the substitution done for those purposes. Say a business shows its own main number when a call goes out from a different line, so the customer can call back and reach someone. The rule describes that in none of its terms.

The statute then goes the other way on a related question. Nothing in that subsection may be construed to prevent or restrict any person from blocking the capability of a caller identification service. In plain terms, showing nothing is protected outright, and the rule adds that blocking your own information is not a violation.

The exceptions are worth reading because they are so narrow. One covers lawfully authorized investigative, protective or intelligence activity by a law enforcement or intelligence agency. The other covers activity under a court order that specifically authorizes caller identification manipulation. There is no business exception. That is the point: none is needed, because ordinary use does not meet the intent condition.

In practice

This comes up whenever a business adds tracking numbers, a receptionist service, or a phone system that routes through somewhere else. The question to answer is not whether the displayed number differs from the originating line, since it almost always will. It is whether the number shown leads back to you, and whether anything about the arrangement is designed to mislead the person receiving the call.

Not the same as

Call tracking
That assigns different numbers to different sources so you can tell where a call came from. What the phone shows is a separate decision.
Blocking your number
The statute protects that explicitly, and the rule says doing it to your own information is not a violation.

Why it matters to you

Businesses hear that spoofing is illegal and conclude that any number substitution is risky. Then they avoid useful tools, or use them nervously. The rule is narrower than its reputation, and the words that narrow it are the intent to defraud, cause harm, or wrongfully obtain anything of value. That turns a vague worry into a question you can answer before choosing a phone setup.

What to ask or check

  1. 01Does the number we display reach us when somebody calls it back?
  2. 02Is there anything about the display that would mislead the person answering about who is calling?
  3. 03If a vendor offers number substitution as a feature, what do they say it is for?

What people get wrong

That showing any number other than the originating line is prohibited. Both the statute and the rule attach the prohibition to an intent to defraud, cause harm, or wrongfully obtain anything of value.

Red flags

  • A displayed number that nobody answers when it is called back.
  • A vendor selling number substitution on the basis that it improves answer rates by disguising who is calling.
  • An arrangement nobody can explain the purpose of, since purpose is what the rule turns on.

Who owns it

The person or entity causing the transmission, which includes a business using a vendor's system. Reading the rule takes two minutes and it is written in ordinary words.

Where you will see it

In call tracking setups, hosted phone systems, and anything that places calls on your behalf.

Call tracking

Call tracking replaces the phone number shown to a visitor with a substitute number that routes to your real one. Only calls dialed through that substitute are measured. Google assigns a forwarding number when call reporting is on, and Microsoft requires an ad group to have reached 10 clicks and 10 dollars of spend in 30 days.

Robocall

A robocall is an outbound call that plays a recorded message. The Telemarketing Sales Rule prohibits placing one to sell something unless the person gave express agreement in writing beforehand. The rule covers calls you place. A system that answers calls coming in to you is a different thing.

Telemarketing Sales Rule

The Telemarketing Sales Rule is the FTC rule governing sales calls. Beyond the do not call list, it sets what a caller must say and when they may call: residential calls only between 8am and 9pm local time, and a prompt disclosure that the purpose of the call is to sell something.

AI voice calls

An AI voice call uses a synthesized or cloned voice to speak to the person who answers. In February 2024 the FCC confirmed those voices fall under the existing rules on artificial or prerecorded voice, so the same consent requirements apply. The message must also identify your business and offer an automated way to opt out.

National Do Not Call Registry

The National Do Not Call Registry is the federal list of numbers telemarketers may not call. Sellers subscribe by area code, and FTC guidance says call lists must be scrubbed against it at least every 31 days. Business to business calls are largely outside the rule, with narrow exceptions.

STIR/SHAKEN

STIR/SHAKEN is how phone carriers sign outbound calls so the receiving network can tell the caller ID was not faked. The signature is your provider attesting to the accuracy of the number it is sending. Congress required it on internet protocol networks and asked only for reasonable measures elsewhere.

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