The code to block your number is *67 on most US phone networks

Dial *67 before the phone number you want to call, then press the call button. The person who receives the call will see "Private Number," "Blocked," or no caller ID at all instead of your phone number. This works on landlines and most mobile phones, whether you use AT&T, Verizon, T-Mobile, or a smaller carrier.

The blocking lasts only for that single call. The next time you dial someone, your number shows normally unless you use *67 again. This is different from permanently blocking your number in your phone's settings, which hides your number on every outgoing call you make.

If you're calling from a business line, a VoIP service like Google Voice, or a phone system at work, *67 may not work or may work differently. Some business phone systems strip out the *67 code before the call goes through. If you're calling from a landline through a PBX system (a phone system that routes calls through a central office), check with your phone provider or IT department first.

Key Takeaways

  • Dial *67 before the number you want to call to hide your number for that single call only.
  • The recipient will see "Private Number" or "Blocked" instead of your caller ID.
  • *67 works on most US carriers and both landlines and mobile phones, but may not work on business phone systems or VoIP services.
  • If *67 doesn't work, your carrier may have a different code, or the recipient's phone may be set to reject blocked calls.
  • Permanently blocking your number on every call requires changing your phone settings, not using a code for each call.

When *67 doesn't work or the call doesn't go through

Some phones and carriers have issues with *67. If you dial *67 and the call fails or goes to an error message, try these steps: first, check that you're dialing *67 before the full phone number, including the area code. Second, wait a few seconds after dialing *67 before pressing the call button—some older phone systems need a moment to process the code.

If the call still doesn't go through, your carrier may use a different code. A few smaller carriers and some regional phone companies use 141 instead of *67, though this is rare in the US. Call your phone provider's customer service line to ask what code they support for blocking your number.

The recipient's phone settings can also block your call. Many phones have a setting to reject calls from blocked or private numbers. If someone has turned on that setting, your call will go straight to voicemail even if you successfully block your number. There's no way around this—the person has chosen not to receive calls from hidden numbers.

The difference between blocking one call and blocking your number permanently

Using *67 hides your number for a single call. Once that call ends, your number is visible again on your next call unless you use *67 again. This is useful when you want to reach someone without giving them your number, but you don't want to hide your number on every call you make.

If you want to hide your number on every call, you can change your phone's settings instead. On an iPhone, go to Settings > Phone > Show My Caller ID and turn it off. On an Android phone, open the Phone app, tap the three-dot menu, go to Settings > Calls, and look for a "Caller ID" or "Show My Number" option—the exact location varies by phone model and carrier. Once you turn this off, your number stays hidden until you turn it back on.

Permanently blocking your number this way affects all your outgoing calls. Some people do this because they have privacy concerns or prefer not to share their number. However, some services—banks, government offices, and customer support lines—may not accept calls from blocked numbers, so you may need to turn your caller ID back on to reach them.

Why someone might want to block their number

People block their number for many reasons. You might not want a business or service to have your personal number. You might be calling someone you don't know well and prefer not to share your contact information. You might be concerned about your privacy or safety and want to limit who has access to your number.

Blocking your number is legal in the United States. However, some situations have limits. If you call 911, your number cannot be blocked—emergency services need your location and contact information. If you're calling a business that requires caller ID to process your call (like a bank verifying your account), blocking your number may prevent the call from going through.

Repeatedly calling someone with a blocked number and hanging up, or using *67 to harass someone, is illegal and can result in charges for harassment or making threatening calls. The code itself is legal, but how you use it matters.

What the person receiving your blocked call sees

When you use *67, the person who receives your call sees one of several things on their phone screen: "Private Number," "Blocked," "Unknown," or sometimes just no information at all. The exact wording depends on their phone model and carrier. Some phones show a generic message like "Restricted" or "Out of Area."

The person can still answer the call and talk to you normally. They just won't see your phone number. If they ask who you are, they're asking because your number didn't come through—not because something is wrong with the call. The call quality and connection are the same as a normal call.

If the person has set their phone to reject blocked calls, the call won't ring through at all. Instead, it will go directly to voicemail, or the call will fail with a message saying the number is not accepting blocked calls. You'll hear this on your end, and you'll know the call didn't go through.

International calls and *67

If you're calling someone outside the United States, *67 may not work. Different countries have different systems for blocking caller ID. Some countries don't support caller ID blocking at all, or they use different codes.

If you're calling from the US to another country, try dialing *67 first, then the country code and number. If that doesn't work, your call will likely go through with your number visible. If you're calling from outside the US, check with your local phone provider about how to block your number in that country.

Some international calling services and VoIP apps have their own settings for hiding your number. If you use an app like WhatsApp, Skype, or Google Voice to make calls, look in the app's settings for a caller ID or privacy option rather than relying on *67.

When you might not want to block your number

Blocking your number can prevent important calls from going through. If you're calling a bank, a doctor's office, a government agency, or a business that uses automated systems, the call may fail or be routed incorrectly if your number is blocked. These organizations often use caller ID to route calls to the right department or to verify your identity.

If you're calling someone for the first time and they don't know you, blocking your number might make them less likely to answer. Many people are cautious about answering calls from blocked numbers because they associate them with spam or scams. If you want the person to take your call seriously, showing your number is usually better.

If you're trying to build a relationship or follow up with someone, blocking your number sends a signal that you want to hide your identity. This can create distrust. For most personal and professional calls, letting your number show is the clearer choice.

Frequently Asked Questions

Can someone find out my number if I use *67?

Not through the phone call itself. Your number won't appear on their caller ID. However, if they have other ways to identify you—like recognizing your voice, or if you tell them your number during the conversation—they can learn who you are. Some advanced phone systems used by law enforcement can trace blocked calls, but regular people and businesses cannot.

Does *67 work on cell phones?

Yes, *67 works on most US cell phones from major carriers like AT&T, Verizon, and T-Mobile. Some smaller carriers and prepaid services support it, but not all. If it doesn't work on your phone, call your carrier to ask if they support caller ID blocking and what code to use.

What if I accidentally block my number and want to unblock it mid-call?

You can't unblock your number during a call that's already in progress. Once the call connects with your number blocked, it stays blocked for that call. You would need to hang up and call again without using *67. For future calls, don't dial *67 before the number.

Can I block my number when texting?

No, *67 only works for voice calls. Text messages don't use the same system as phone calls, so there's no code to block your number on SMS. If you want to send a text without revealing your number, you would need to use an app like Google Voice or a similar service that masks your identity.

Will blocking my number prevent spam filters from catching my call?

No, blocking your number doesn't affect spam detection. Some people think that using *67 will help them avoid being flagged as spam, but spam filters look at many things beyond caller ID—the number of calls made, patterns of calling, and whether the number is on a known spam list. Blocking your number won't change how filters treat your call.