How to Block Your Number When Making a Call

Most phones make your number visible to whoever you're calling — it shows up on their screen before they even pick up. But there are legitimate reasons you might not want that. Calling a business you don't fully trust, reaching out to someone you'd rather not give your personal number to, or simply maintaining privacy on a one-off call are all common scenarios.

The good news: blocking your number is straightforward. The mechanics vary slightly depending on your device, carrier, and the type of call you're making — but the core options are consistent across most setups.

What "Blocking Your Number" Actually Does

When you block your number, you're suppressing your Caller ID — the signal your phone sends that tells the recipient's network who is calling. Instead of your number, the recipient sees "Private," "Unknown," "Blocked," or "No Caller ID," depending on their carrier and device.

This is done using a protocol called CLIR (Calling Line Identification Restriction), which is supported by virtually all modern phone networks. Your number isn't deleted or hidden from the carrier — your carrier always knows who placed the call — but it isn't passed along to the person you're calling.

One important limitation: some numbers can't be blocked to. Emergency services (like 911) will always receive your number regardless of your settings. Some businesses also use CNAM (Caller Name) lookup or third-party services that can partially de-anonymize blocked calls, though this is less common for personal use.

The Quick Method: Per-Call Prefix Code

The fastest way to block your number on a single call is to dial a prefix before the number. This is temporary — it only applies to that one call.

In the US, dialing *67 before any number will suppress your Caller ID for that call only. You dial it, it connects as private, and your next call goes out as normal. No settings changed, no permanent adjustments made.

This works on both cell phones and landlines in most cases, though landline support can vary by carrier.

Permanent Caller ID Blocking: System-Level Settings

If you want every call you make to go out as private by default, you have two main routes: phone settings or carrier-level settings.

On iPhone (iOS)

Go to Settings → Phone → Show My Caller ID and toggle it off. This suppresses your number on all outgoing calls. If you need to un-block for a specific call while this is on, you can dial *82 before the number — that temporarily re-enables Caller ID for just that call.

On Android

The path varies slightly by manufacturer and Android version, but generally:

Phone app → Settings (or three-dot menu) → Calls → Additional Settings → Caller ID → Hide Number

Some Android skins (Samsung One UI, for example) label this slightly differently, but the option is typically under call or supplementary settings.

Through Your Carrier

Most major carriers allow you to request permanent Caller ID blocking at the account level. This is done by calling customer support or, in some cases, through your online account portal. Carrier-level blocking tends to be more reliable than device-level settings because it applies regardless of what app or device you're using to make calls.

📱 What About VoIP and App-Based Calls?

This is where things get more variable. If you're calling through apps like WhatsApp, FaceTime, Google Voice, or Zoom, the Caller ID rules change.

• Google Voice lets you choose what number displays — you can use your Google Voice number instead of your real mobile number, which functions as a built-in layer of number privacy.
• WhatsApp and FaceTime calls show your account-linked phone number or Apple ID to the recipient. The *67 prefix and system-level Caller ID settings generally don't apply to these calls.
• Third-party VoIP apps vary widely — some allow display number customization, others don't.

If call privacy matters to you across all types of calls, you need to check the settings within each platform separately. A blanket "hide my number" setting on your phone won't automatically carry over to app-based calling.

Variables That Affect How This Works for You 🔒

The method that makes sense depends on several factors:

• How often you need to block — occasional blocking favors *67; regular blocking favors a system or carrier setting
• What type of calls you're making — carrier calls vs. VoIP apps follow different rules
• Your carrier's policies — some prepaid or MVNO carriers handle CLIR differently than major postpaid carriers
• Your device and OS version — older Android versions or heavily customized manufacturer UIs sometimes bury or restrict Caller ID settings
• Whether you also need to receive calls privately — blocking your outbound Caller ID does nothing to stop incoming callers from seeing your number when they call you

The technical mechanisms are consistent, but which combination of method and setting actually fits your situation depends on how you're calling, how often, and what outcome you're actually trying to achieve.