Why you might want to block your number

Blocking your number — technically called caller ID blocking — hides your phone number from the person you are calling. They see "Unknown," "Private," or "Blocked" instead of your digits. This is useful when you want privacy for a single call, or when you are calling someone who might not pick up if they see your number.

The difference between blocking one call and blocking all calls matters. You can block your number for every call you make (permanent blocking), or hide it just for calls you choose (per-call blocking). Both are free features on most phone plans, though some carriers charge a small monthly fee if you want permanent blocking.

Key Takeaways

  • You can block your number for a single call by dialing *67 before the phone number on most landlines and cell phones in the United States.
  • To block your number on all calls, contact your phone carrier — the setting lives in your account, not on your phone itself.
  • Some carriers charge $2 to $4 per month for permanent blocking; others include it free with your plan.
  • The person you call may still see your number if they have a service that unblocks private calls, or if you are calling a business, hospital, or government office.
  • Blocking your number does not prevent the call from going through — it only hides your identity from the recipient.

Blocking your number for a single call

The fastest way to hide your number on one call is to dial *67 before the phone number. Type *67, then the full number including area code, then press call. The person who answers will see a blocked or private number instead of yours.

This works on most landlines and cell phones in the United States. If you are calling from outside the US, the code may differ — Canada uses *67 as well, but the UK uses 141, and other countries have their own codes. Check with your carrier if you are unsure.

The block lasts only for that one call. The next time you call someone, your number shows up normally unless you dial *67 again. This method is free on all carriers.

Blocking your number on all outgoing calls

If you want your number hidden every time you call, you need to change the setting in your phone account with your carrier. This is not a setting on your phone — it is a setting on the carrier's network. You cannot do it through your phone's settings menu.

Contact your carrier directly by phone, through their website, or in person at a store. Tell them you want to enable caller ID blocking or anonymous calling on your account. They will walk you through the process, which usually takes a few minutes. Some carriers let you turn it on and off through their app or online account portal once it is set up.

Ask your carrier whether there is a fee. Most major carriers — AT&T, Verizon, T-Mobile, and most regional carriers — offer this free or for $2 to $4 per month. Some include it free with certain plan types. The fee, if any, appears on your monthly bill.

When blocking your number does not work

Blocking your number is not foolproof. Hospitals, police departments, banks, and other institutions often have systems that override caller ID blocking and see your real number anyway. If you call a business with a modern phone system, they may also see through the block.

Some people pay for services that unblock private numbers — these are less common than they used to be, but they still exist. If someone has this service, they will see your number even if you blocked it.

If you are trying to hide your number from someone who has your contact information in their phone, blocking your number will not help — they already know who you are. Caller ID blocking only hides your number from people who do not recognize it.

Unblocking your number if you change your mind

If you dialed *67 and want to undo it for future calls, straightforward stop dialing *67. Each call is independent — there is nothing to turn off.

If you set up permanent blocking through your carrier and want to turn it off, call your carrier again and ask them to disable caller ID blocking on your account. This usually takes one call and takes effect within a few minutes. If you set it up through their app or online portal, you can usually toggle it off the same way you turned it on.

Blocking versus other privacy options

Caller ID blocking hides your number but does not prevent the call from being recorded or traced by law enforcement if needed. If you are concerned about a call being recorded, blocking your number will not stop that — it only hides your identity from the person answering.

If you want to make a call without using your own phone number at all, you can use a different phone, a calling app like Google Voice or Skype (which assigns you a different number), or a calling service. These are different from blocking — they give you a different number rather than hiding yours.

Frequently Asked Questions

Will *67 work on my cell phone?

Yes, *67 works on most cell phones in the United States on both Android and iPhone. Dial *67 before the number, then call as normal. If it does not work, contact your carrier — some prepaid plans or older services may not support it.

Can I block my number when texting?

No. Caller ID blocking only works for voice calls. Text messages always show your number or the name associated with your account. There is no *67 equivalent for SMS.

What if the person I called has my number saved in their phone?

They will still see your name or contact information if they have you saved, even if your number is blocked. Blocking only hides the number itself from people who do not already know who you are.

Does blocking my number cost money?

Per-call blocking with *67 is free. Permanent blocking through your carrier may be free or cost $2 to $4 per month depending on your carrier and plan. Ask your carrier about the cost before you set it up.

Can someone trace my number if I block it?

Law enforcement can trace a blocked call if they have a warrant. Hospitals and emergency services can also see your real number. For regular people, a blocked number is much harder to trace, but it is not impossible if they have the right tools or services.