How to Block Caller ID on a Cell Phone

Blocking your caller ID means the person you're calling sees "Unknown," "No Caller ID," or "Private Number" instead of your phone number. It's a straightforward feature built into virtually every mobile network — but the exact method varies depending on your device, carrier, and how permanently you want it applied.

Why People Block Their Caller ID

There are plenty of legitimate reasons to hide your number. Professionals returning calls from a personal phone, individuals protecting privacy from unknown contacts, or people calling businesses they'd rather not have stored in a database all use this feature routinely. It's legal in most countries for standard voice calls, though emergency services (911 in the US) can always see your number regardless of any blocking setting.

Method 1: The *67 Prefix (Per-Call Blocking)

The fastest and most universally supported method is dialing *67 before any number in the US and Canada. For example:

*67-555-867-5309 

This hides your number for that single call only. Your caller ID returns to normal on the next call. It works on virtually all carriers and both Android and iOS devices without changing any settings.

📞 International equivalents differ by country. The UK uses 141, Australia uses 1831, and many European countries use #31# placed before the number. If you're traveling or calling internationally, the *67 code may not apply.

Method 2: Changing Your Default Caller ID Setting (Permanent Blocking)

Both Android and iOS allow you to hide your number by default for all outgoing calls.

On iPhone (iOS)

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

The option may be grayed out on some carrier plans. If it is, your carrier controls this setting and you'll need to request the change through them directly.

On Android

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

1. Open the Phone app
2. Tap the three-dot menu or Settings
3. Select Calls or Call Settings
4. Tap Additional Settings or Supplementary Services
5. Select Caller ID
6. Choose Hide Number

Samsung, Pixel, and other OEM devices may label these menus slightly differently. Some Android skins bury this under Call Accounts or behind a specific SIM card selection if you're using a dual-SIM phone.

Method 3: Carrier-Level Blocking

Most major carriers — including AT&T, Verizon, T-Mobile, and their MVNOs — offer permanent caller ID blocking applied at the network level rather than the device level. This means the setting follows your number, not your phone, so it works even if you switch devices.

To request carrier-level blocking, contact your carrier's customer support directly. Some carriers offer this free; others may require a specific plan or add-on.

What Caller ID Blocking Doesn't Do

Understanding the limits matters before you rely on this feature:

• Toll-free numbers (1-800, etc.) can still see your number — services using toll-free lines often receive your caller ID regardless of blocking
• Emergency services always receive your number, even when blocked
• Third-party apps like Google Voice, WhatsApp, or VoIP services have their own caller ID rules — blocking on your native dialer doesn't carry over to calls made through apps
• Some carriers or recipients may reject blocked calls entirely, depending on their spam-filtering settings

📱 VoIP and App-Based Calls Are a Different Story

If you regularly make calls through apps — Google Voice, Skype, WhatsApp, or a business VoIP platform — the caller ID is tied to that app's assigned number, not your SIM card. Blocking works differently in each:

• Google Voice lets you call from your Google Voice number, effectively masking your real number by default
• WhatsApp shows your WhatsApp-linked number, and call blocking happens within the app's privacy settings
• Business VoIP platforms often give you an admin-controlled caller ID that's separate from personal blocking settings

This is a meaningful distinction if privacy across all call types is the goal.

Variables That Affect Which Method Works Best for You

No single method suits every situation. The right approach depends on factors specific to your setup:

• Your carrier — some carriers restrict device-level caller ID controls, forcing you to use *67 or request account-level changes
• Your OS version and device manufacturer — older Android versions or heavily customized OEM interfaces may not expose the caller ID setting in the expected location
• SIM vs. eSIM or dual-SIM setup — each line may need to be configured independently
• How often you need blocking — occasional privacy calls favor *67; consistent need favors a permanent setting
• Call type — native dialer calls, VoIP calls, and app-based calls follow separate rules
• Country — blocking codes and carrier policies vary significantly outside North America

The technical capability exists across virtually all modern phones and carriers, but whether the default setting is accessible to you — or controlled at the carrier level — depends entirely on your account, device, and region. That's the piece only your specific setup can answer.