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Blocked and anonymous calls

How to make an anonymous phone call

Reviewed by Sujan ThapaliyaLast updated

The short answer

Dial *67 immediately before the number in North America, or 141 in the UK and much of Europe, and your caller ID is withheld for that call only. The recipient sees Private, Restricted or No Caller ID depending on their handset. Your number is still recorded by the carriers.

There are two ways to withhold a number and four situations in which it is passed anyway. Both halves matter, because people withhold expecting anonymity and get something narrower than that.

How do you withhold your number for one call?

  1. 1

    Dial the prefix first

    *67 in the United States and Canada, 141 in the United Kingdom and much of Europe. Enter it immediately before the number, with no space or pause.
  2. 2

    Dial the full number

    Include the area code even for a local call. The prefix applies to the number that follows it, so a partial number will simply fail.
  3. 3

    Check what the other end sees

    Call your own second phone first. You will see exactly what your recipients see, which is worth knowing before it matters.
The label is chosen by the receiving handset, not by you — the same call reads differently on different phones.
Where you arePer-call withholdingWhat the recipient sees
United States, Canada*67No Caller ID, Private, or Restricted
United Kingdom, Ireland141Withheld or No Caller ID
Most of Europe141 or #31#Anonymous or Private
Many GSM networks worldwide#31#Varies by handset

When your number is passed anyway

  • Toll-free numbers. They receive the originating number through the billing signalling because the called party pays for the call. Withholding hides it from the display, not from the business.
  • Emergency services. Always, by design, and no prefix changes it.
  • Some business phone systems. Systems that read the signalling identity rather than the display value see the number in the same way a toll-free line does.
  • Your own carrier's records. Withholding is a display instruction, not a deletion. Every call is logged with the originating number.

Withholding is not anonymity

It hides your number from a screen. If the goal is genuinely to not be identified, a withheld call from your own line does not achieve it — and using it to deceive someone crosses into the Truth in Caller ID Act.

Why businesses should do the opposite

Withheld calls are answered at a fraction of the rate identified calls are, and none of them can be returned. For a business that is the whole game: the callbacks are the calls most likely to convert, and a withheld number throws them away before the conversation starts.

The productive version of the same instinct — controlling what the recipient sees — is to control it deliberately: your business name on the display through CNAM, the call signed so the carrier trusts it, and a number that reaches your team when they call back. That is covered in branded caller ID and in why calls show as Spam Likely.

Frequently asked questions

What is the code to call anonymously?
*67 in North America and 141 in the UK and much of Europe, dialled immediately before the full number with no pause. It withholds caller ID for that call only; the next call you place is identified again.
Is calling anonymously illegal?
Withholding your number is legal in itself. Doing it with intent to defraud, cause harm or wrongfully obtain something of value is not — that is the Truth in Caller ID Act, and the offence is the intent rather than the withholding.
Can the person I called still find out my number?
Not from their handset. The carriers hold it for billing and regulatory records, and law enforcement can obtain it through proper process, but it is not exposed to the recipient. Services claiming to unmask withheld calls generally cannot.
Does *67 work on every call?
No. Toll-free numbers receive the originating number through billing signalling regardless, emergency services always receive it, and some business systems capture it the same way toll-free lines do. Withholding is not anonymity in those cases.
How do I withhold my number on every call?
Ask your carrier to enable line-level caller-ID blocking, or set it in your account. Consider what it costs first: withheld calls are answered far less often, and nobody can return them.

Sources

  1. Combating Spoofed Robocalls with Caller ID Authentication — Federal Communications CommissionThe STIR/SHAKEN framework, the attestation levels carriers sign calls with, and the mandate requiring providers to authenticate caller ID.
  2. 47 CFR Part 64 — Miscellaneous Rules Relating to Common Carriers — Electronic Code of Federal RegulationsThe operative federal rules on caller ID transmission, call authentication, and robocall mitigation.

Stop working around the phone system

Carrier codes exist because the line was never built for a business. Owned numbers, routing rules, voicemail and recording in one place, priced on usage.

  • No seat licences
  • Numbers you own
  • Compliance built in
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