What blocking your number means and how it works

When you block your number before calling someone, that person's phone displays "Unknown," "Private," or "Blocked" instead of your phone number. The call still goes through — they can answer it — but they cannot see who is calling them. This is different from blocking a caller (where you prevent calls from reaching you). You are controlling what information your phone sends out about you.

Your phone number is transmitted to the receiving phone through a system called Caller ID. When you block your number, you are instructing your phone company not to send that information along with your call. The receiving phone has no way to override this — they straightforward do not receive the data.

How this works depends on whether you want to block your number for a single call or for all calls you make. The steps are different, and the availability depends on your phone type and carrier.

Key Takeaways

  • You can block your number for one call by dialing *67 before the phone number on most landlines and many cell phones in the United States.
  • To block your number for all calls, you must contact your phone carrier or adjust settings in your phone's calling app, depending on your device type.
  • Some carriers charge a monthly fee to block your number on all outgoing calls, while blocking a single call is free.
  • The person you call will see "Unknown" or "Blocked" instead of your number, but they can still answer the call and hear you.
  • Blocking your number does not prevent emergency services from seeing your location if you call 911.

Blocking your number on a single call with *67

The fastest way to hide your number on one call is to use the code *67. This works on most landlines and many cell phones in the United States, though not all carriers support it.

Here is the exact step: Before you dial the phone number, type *67 first. Then dial the number normally. For example, if you are calling 555-123-4567, you would dial *67-555-123-4567 or *67 555-123-4567 (spacing does not matter). Press call. The person who answers will see "Unknown" or "Blocked" instead of your number.

If *67 does not work, your carrier may not support it, or you may have a setting that overrides it. Try the next section instead. If you use a calling app like Google Voice or Skype rather than your phone's native dialer, *67 may not work — check that app's settings menu for a privacy or blocking option.

Blocking your number on all outgoing calls through your carrier

If you want your number blocked on every call you make, you need to contact your phone carrier directly. The process and cost vary by carrier.

For major carriers: Call AT&T at 611 from your phone or 1-800-331-0500, Verizon at 611 or 1-908-559-4899, T-Mobile at 611 or 1-844-839-4534, or your local carrier's customer service number. Ask to set up "Caller ID Blocking" or "Anonymous Call Rejection" (the exact name varies). Some carriers offer this free; others charge $1 to $3 per month. Ask the cost before you confirm.

The carrier will set up it on your account, and it takes effect within one to two business days. Once it is on, every call you make will show as blocked unless you override it for a specific call (see the next section).

Unblocking your number for specific calls when you have it blocked on all calls

If you have set your number to be blocked on all calls but want one person to see your actual number, you can override it for that single call. The code is *82.

Dial *82 before the phone number, the same way you would dial *67. For example, *82-555-123-4567. That call will show your real number to the person receiving it, even though all your other calls remain blocked.

This only works if your carrier supports it and if you have already set up full number blocking through them. If you are just using *67 for individual calls, you do not need *82.

Blocking your number on iPhone

iPhones do not have a built-in setting to block your number on outgoing calls. You cannot use *67 through the native Phone app on most iPhones. Instead, you have two options.

The first option is to contact your carrier and set up full number blocking through your account (see the carrier section above). Once your carrier has it activated, every call from your iPhone will be blocked automatically.

The second option is to use a calling app that supports number blocking, such as Google Voice. Open Google Voice, go to Settings, and look for a "Caller ID" or "Display outgoing caller ID" option. You can turn this off so calls show as blocked. This only affects calls made through the Google Voice app, not calls made through your phone's regular Phone app.

Blocking your number on Android

Android phones vary by manufacturer and carrier, so the steps are not the same for every device. Some Android phones support *67 through the native Phone app; others do not.

Try *67 first. If it works, you will see a message confirming that your number is blocked for that call. If it does not work or you want to block your number on all calls, contact your carrier using the phone numbers in the carrier section above.

If you use Google Voice or another calling app on Android, open the app and look for Settings. Find the option for "Caller ID" or "Display my number" and turn it off. Calls made through that app will then show as blocked.

Why blocking your number might not work

If you try *67 and the call still shows your number, your carrier may not support it, or you may have a setting that overrides it. Some carriers, particularly older landline services, do not allow number blocking at all.

If the person you are calling has set their phone to reject blocked calls, they will not receive your call at all — it will go to voicemail or be rejected. There is no way around this on your end. You would need to call from a different number or ask them to change their phone settings.

If you are calling a business, government office, or customer service line, many of these numbers automatically reject blocked calls for security reasons. You may need to unblock your number to reach them.

Frequently Asked Questions

Does *67 work on all phones and carriers?

No. *67 works on most landlines and many cell phones in the United States, but not all carriers support it. If you dial *67 and your number still shows up, your carrier does not offer it. Contact them to set up full number blocking instead, or try a calling app like Google Voice.

Can someone trace my call if I block my number?

A regular person cannot see your number if you block it. However, law enforcement can trace blocked calls if they have a court order, and 911 services can always see your location regardless of blocking. Blocking your number only hides it from the person you are calling.

Will blocking my number prevent me from leaving a voicemail?

No. If the person does not answer, your call will go to voicemail, and you can leave a message. The voicemail will show as from a blocked number, but the message itself will record normally.

What is the difference between *67 and asking my carrier to block my number?

*67 blocks your number for one call only and is free. Asking your carrier to block your number sets it up for all calls and may cost $1 to $3 per month, depending on the carrier. Once your carrier has it set up, you do not have to dial anything — it happens automatically.

If I block my number, can the person I call still see my name?

No. When you block your number, the receiving phone displays "Unknown," "Private," or "Blocked" — not your name. The person has no information about who is calling.