What *67 does and doesn't do

Dialing *67 before a phone number blocks your caller ID on that single call — the person you're calling sees "Private Number," "Blocked," or no number at all instead of your phone number. It works on most landlines and mobile phones in North America, and it's built into your phone service at no extra cost.

But *67 has real limits. It doesn't hide your number from the phone company itself, from law enforcement with a warrant, or from businesses that have tools to unmask blocked calls. It also doesn't work on toll-free numbers, directory information, or 911 calls — those systems either ignore the block or override it automatically. If you call someone's voicemail, they may still see your number when they retrieve the message, depending on their carrier.

The feature exists because some people need temporary privacy for legitimate reasons: calling a doctor's office from work, reaching a domestic violence shelter, or contacting a business without giving out your personal number. It's not illegal to use, but repeatedly calling someone with *67 and hanging up, or using it to harass or threaten someone, is.

Key Takeaways

  • Dialing *67 before a phone number hides your caller ID on that one call only — you have to dial it each time.
  • The person you call sees a blocked or private number, but your phone company has a record of the call and can share it with law enforcement if they have a warrant.
  • *67 does not work on calls to toll-free numbers, 911, or directory information, which either ignore the block or bypass it.
  • Voicemail systems may still display your number even if you used *67, depending on your carrier and their setup.

How *67 actually works on your phone

When you dial *67 followed by a phone number, you're sending a signal to your phone company's switching system before the call connects. That signal tells the system to suppress the Calling Line Identification (CLID) data — the number your phone normally broadcasts to identify you. The receiving phone never gets that data, so their caller ID display has nothing to show.

The suppression happens only for that single call. If you hang up and call the same person again without dialing *67, your number will show normally. Some older phone systems and certain business phone lines may not recognize the *67 command at all, in which case your number displays anyway.

On mobile phones, *67 works the same way — it's a standard feature built into your carrier's network, not something you read or turn on in settings. You dial it the same way you would on a landline: *67, then the number, then send.

What the phone company knows and what they'll share

Your phone company keeps detailed records of every call you make, including calls placed with *67. Those records show your phone number, the number you called, the date, the time, and the duration — even though the person you called couldn't see your number. The *67 block only affects what the receiving phone displays; it doesn't erase the call from the phone company's logs.

Law enforcement can request those records with a warrant, subpoena, or court order. In emergencies, some carriers will release call records without a warrant, depending on their policy and the circumstances. The phone company will not voluntarily share your identity with someone who received a blocked call from you — they require legal process first.

If a business or individual wants to know who called them with *67, they cannot contact the phone company and ask. They would need to go through law enforcement or the courts. Some businesses use third-party services that claim to unmask blocked calls, but those services work by other means (like reverse phone lookup databases) and are not accessing phone company records directly.

When *67 doesn't work or gets overridden

Toll-free numbers (800, 888, 877, 866 numbers) do not respect *67 blocks. When you call a toll-free number, your caller ID information goes through to the business anyway, regardless of whether you dialed *67. This is by design — toll-free services are set up to capture caller information for routing and tracking purposes.

Emergency calls to 911 always bypass *67. Even if you dial *67 before 911, the dispatcher receives your phone number and location data automatically. The system is designed this way so emergency responders can reach you if the call drops.

Calls to directory information and some automated systems also ignore *67. If you call 411 or a similar service with *67, your number may still be recorded in their system. Voicemail and call-return features (*69 or similar) may also reveal your number to the person you called, even if you used *67 on the initial call.

Why someone might use *67 and what it actually protects

People use *67 for many ordinary reasons. A job applicant might call a company's main line to ask about the hiring process without giving out their personal number. Someone might contact a medical office from their workplace without broadcasting their work number. A person researching a business or service might want to ask questions without being added to a sales call list.

In more serious situations, *67 can provide a layer of privacy for people reaching out to domestic violence resources, addiction support lines, or other sensitive services. It's not a complete shield — the organization still has a record of the call — but it prevents your number from appearing on your phone bill in a way that someone with access to your bill might recognize.

What *67 does not protect you from: someone recording the call (which is legal in some states and illegal in others, depending on consent laws), someone writing down information you give them verbally, or someone using other methods to identify you. It also doesn't hide your identity if you give your name or other identifying details during the conversation.

The difference between *67 and other privacy features

Some carriers offer a service called "Permanent Call Block" or "Anonymous Call Rejection," which is different from *67. These are settings you turn on in your account that either permanently block your number from showing on all your calls, or that reject incoming calls from blocked numbers. You have to contact your carrier to set these up, and they may cost extra or be included in certain phone plans.

VoIP services like Google Voice or Skype let you make calls from a different number entirely — not your personal phone number. That number is tied to your account, so it's still traceable to you through the service, but the person you call sees the VoIP number instead of your personal one. This is different from *67, which hides your real number but doesn't replace it with a different one.

Text messages do not have a *67 equivalent. If you text someone, your phone number is embedded in the message and cannot be hidden with a code. Some messaging apps let you text without revealing your phone number, but those are separate services, not a feature of standard SMS.

Legal and practical things to know

Using *67 is legal. There is no law against dialing it or using it to make a private call. However, using *67 repeatedly to call someone and harass them, threaten them, or commit fraud is illegal — the illegality comes from the harassment or fraud itself, not from the blocked number.

Some businesses and organizations have policies against accepting calls from blocked numbers. They may not answer, or they may ask you to unblock your number before they'll help you. Government offices, banks, and customer service lines sometimes do this. If a blocked call is rejected, you can call back without *67 or ask the organization what their policy is.

If you're trying to reach someone who has blocked your number, *67 will not help you get through. Call blocking is a separate feature that prevents calls from a specific number from reaching the phone at all. *67 only hides your number from the caller ID display; it doesn't bypass someone's block list.

Frequently Asked Questions

Can someone trace a *67 call back to me?

The person you called cannot trace it themselves. But if they report the call to law enforcement and the police get a warrant, the phone company can provide your number from their records. The *67 block only affects what shows on their phone — it doesn't erase the call from the phone company's system.

Will *67 work on my cell phone?

Yes, *67 works on most cell phones in the United States and Canada. You dial it the same way: *67, then the number, then send. Some carriers or older phone systems may not support it, but major carriers (Verizon, AT&T, T-Mobile, etc.) all do.

What if I use *67 and the person calls me back?

They cannot call you back using the blocked number because they never received your actual number. If they have your number from another source (a contact list, a previous call, a text message), they can call that number. But they cannot use the blocked call to reach you.

Does *67 hide my number from my phone bill?

No. Your phone bill shows every call you make, including calls placed with *67. The *67 block only affects what the receiving phone displays — it doesn't change what your carrier records or what appears on your bill.

Can I use *67 on a three-way call or conference call?

*67 only works on the initial outgoing call. Once the call connects, adding other people to the call does not maintain the block. If you're on a three-way call, the other people on the line can see your number if they have caller ID, depending on how the call was set up.