Block your number on a single call

To hide your number on one call, open the Phone app, tap the keypad, and enter #31# before the phone number you are calling. Then press the green call button as usual. The person who answers will see "Unknown" or "Private Number" instead of your caller ID.

This method works for any single call you make. The next call you place will show your number normally unless you repeat the #31# prefix. If you dial the same number multiple times, you need to add #31# each time you want to block your number.

The #31# code works on most carriers in the United States, including Verizon, AT&T, T-Mobile, and others. If it does not work, contact your carrier to confirm the code for your network.

Key Takeaways

  • Enter #31# before any phone number in the Phone app to hide your caller ID for that single call.
  • To block your number on all outgoing calls, go to Settings > Phone > Show My Caller ID and toggle it off.
  • Blocking your number does not prevent the person from calling you back or texting you.
  • Emergency services (911) will always receive your real number even if you have blocking turned on.
  • Some businesses and government offices may refuse to take calls from blocked numbers.

Block your number on all calls

To hide your number on every call you make, go to Settings on your iPhone, then tap Phone. Scroll down and tap Show My Caller ID. Toggle the switch to the off position (it will turn gray). From that point forward, your number will be hidden on all outgoing calls.

This setting stays in place until you turn it back on. You can reverse it at any time by returning to Settings > Phone > Show My Caller ID and toggling it back on. Your carrier may take a few minutes to process the change, so the first call you make after toggling might still show your number.

If you do not see the "Show My Caller ID" option in your Phone settings, your carrier may not support this feature. Contact your carrier directly to ask whether they offer caller ID blocking.

What happens when you block your number

When your number is blocked, the person you call sees "Unknown," "Private Number," "Blocked," or no number at all, depending on their phone and carrier. They can still answer the call and talk to you normally. They can also call you back, text you, or reach you through other means — blocking your outgoing caller ID does not prevent them from contacting you.

Some people do not answer calls from unknown numbers, so blocking your caller ID may increase the chance your call goes to voicemail. Businesses, government offices, and customer service lines often refuse to take calls from blocked numbers entirely. If you need to reach someone who screens unknown callers, you may want to let your number show.

If you leave a voicemail, the person may still be able to identify you from the message content, even though they cannot see your number on the incoming call.

Emergency calls always show your number

If you call 911, your real phone number will be sent to emergency services regardless of whether you have caller ID blocking turned on. This is a legal requirement — emergency dispatchers need your actual number to locate you and call you back if the line disconnects.

The same applies to other emergency numbers like poison control or crisis hotlines. These services override caller ID blocking to may support they can reach you if needed.

Blocking your number versus blocking a contact

Hiding your own caller ID is different from blocking someone else's calls. When you block a contact in your iPhone, that person cannot reach you by phone or text, and you will not see their calls or messages. You can block a contact by opening their entry in your Contacts app, scrolling down, and tapping Block This Caller.

Blocking your number hides your identity from people you call. Blocking a contact prevents a specific person from reaching you. These are separate features that serve opposite purposes.

Carrier-specific options

Some carriers offer additional caller ID management tools through their own apps or websites. Verizon offers Call Filter, AT&T offers Call Protect, and T-Mobile offers Scam Shield. These apps let you block numbers, report spam, and sometimes manage how your caller ID appears on outgoing calls.

Check your carrier's website or app store to see what options are available on your plan. Some features may require a paid subscription, while others are included free with your service.

Frequently Asked Questions

Will the person know my number is blocked if I call them?

No, they will only see "Unknown" or "Private Number" on their phone. They will not receive a notification that you blocked your number. However, if you leave a voicemail or they recognize your voice, they may figure out who called.

Can I block my number for texts?

No, the #31# code and the Show My Caller ID setting only work for phone calls. Text messages always show your phone number or contact name to the recipient. If you want to text someone without revealing your identity, you would need to use a different phone number or a third-party messaging app.

What if Show My Caller ID is grayed out in my settings?

This usually means your carrier does not support caller ID blocking, or your account does not have the feature enabled. Contact your carrier's customer service to ask whether they offer this option and whether it is available on your plan.

Does blocking my number prevent someone from calling me back?

No, blocking your outgoing caller ID does not affect incoming calls. If someone wants to reach you, they can still call your number if they have it, or text you, or contact you through other means. Blocking your number only hides your identity on calls you make.