How to Block Your Number When Making a Call

Blocking your number before a call — so the person on the receiving end sees "Unknown," "Private Number," or "No Caller ID" instead of your digits — is a built-in feature on virtually every modern phone. But the how varies depending on your device, carrier, and how often you need the privacy.

What "Blocking Your Number" Actually Does

When you block your number, you're suppressing your Caller ID information. This is done using a signaling code called CLIR (Calling Line Identification Restriction), which tells the phone network not to pass your number to the recipient's device.

The number doesn't disappear entirely — your carrier still logs it, and emergency services (like 911) can always see it. What changes is what appears on the other person's screen. Instead of your number, they typically see one of these labels depending on their carrier and device: "No Caller ID," "Private Number," or "Unknown."

This is completely legal for personal use in most countries, and it's different from spam or robocall blocking — you're simply exercising your right to privacy on outgoing calls.

Method 1: Per-Call Blocking Using a Prefix Code

The quickest method, and one that works on almost any phone, is dialing *67 before the number you're calling (in the US and Canada). The full dial string looks like this:

*67 + 1 + area code + number 

For example: *67-1-555-867-5309

This suppresses your Caller ID for that one call only. Your number displays normally on every other call. No settings changed, no setup required.

Country variations matter here. The *67 code is specific to North America. Other regions use different codes:

If you're outside North America, check with your local carrier — the prefix varies and using the wrong one may just dial incorrectly.

Method 2: Blocking Your Number Permanently on iPhone

If you want every outgoing call to go out as private by default, you can toggle this in your iPhone's settings:

1. Open Settings
2. Tap Phone
3. Tap Show My Caller ID
4. Toggle it off

Your number will now be hidden on all calls until you turn it back on. If you want a single call to show your number while this is active, you can dial *82 before the number to temporarily unblock it for that call.

⚠️ One catch: some carriers override this setting, particularly on certain prepaid or MVNO plans. If the toggle is grayed out, your carrier may be controlling it. You'd need to contact them directly or use the *67 method instead.

Method 3: Blocking Your Number Permanently on Android

Android doesn't have a single universal path because manufacturers customize the dialer — but the setting usually lives here:

1. Open the Phone app
2. Tap the three-dot menu (top right) or go to Settings
3. Look for Calls, then Additional Settings or Supplementary Services
4. Tap Caller ID
5. Select Hide Number

On Samsung devices specifically, the path is often: Phone app → Settings → More Settings → Caller ID → Hide number.

Like iOS, some Android carriers restrict this option or override it from the network side. If the setting is missing or not working, *67 is the reliable fallback.

Method 4: Blocking Your Number Through Your Carrier

Many carriers let you request permanent Caller ID blocking at the account level — often for free. You call or chat with customer support and ask them to suppress your outbound number by default. This applies regardless of which phone you use on the account, which makes it useful if you switch devices frequently or use multiple phones on one plan.

The tradeoff: you'll need to contact them again to reverse it, and not all carriers offer this as a self-service option.

When Blocking Doesn't Work 📵

There are real limitations worth understanding:

• Calls to 800/900/premium numbers: These services can often see your number regardless of *67 or privacy settings.
• Emergency services: 911 (and equivalent emergency numbers globally) always receive your number.
• Some VoIP and business phone systems: Depending on how they're configured, they may bypass CLIR.
• Contacts who use call-blocking apps: Apps like Hiya or Truecaller may still identify or label your number as private, even if the number itself isn't displayed.

The Variable That Changes Everything

How you should block your number depends on factors specific to your situation — your carrier, your OS version, whether you're on a contract or prepaid plan, and how frequently you need the privacy. A one-off private call is a different need than hiding your number across every call you make. Some setups give you a clean toggle in settings; others are locked down at the carrier level and require a workaround or a direct request.

The mechanics are consistent across most modern phones, but the right method for your specific setup is the piece only your own phone, plan, and use case can answer. 🔒