How to Block Your Number When Calling Out
Most phones display your number to whoever you're calling. That's fine in plenty of situations — but not always. Whether you're calling a business, a stranger from a classified ad, or just want more privacy in general, knowing how to hide your caller ID gives you more control over who sees your personal number.
Here's exactly how it works, what affects it, and what you should know before relying on it.
What "Blocking Your Number" Actually Means
When you make a call, your phone sends your number as part of the call signaling data — this is your Caller ID. The receiving phone (or carrier network) reads that data and displays it on screen before the call is answered.
Blocking your number tells your carrier to suppress that data before it reaches the other end. Instead of your number, the recipient sees "Private Number," "Unknown," "Blocked," or "No Caller ID" — depending on their phone and carrier.
This suppression happens at the network level, not just on your screen. Your number still travels through the carrier infrastructure (so emergency services and certain law enforcement requests can still access it), but it doesn't appear on the recipient's display.
Method 1: Per-Call Blocking with a Prefix Code
The quickest option requires no settings changes at all. Before dialing any number, add *67 first (in the US and Canada). For example:
*67 + 555-867-5309 This tells your carrier to suppress your caller ID for that call only. Once the call ends, your number goes back to displaying normally on your next outgoing call.
📱 This works on most smartphones and landlines in North America. Other regions use different codes — #31# is common in many European countries and parts of Australia.
Method 2: Turning Off Caller ID Globally in Your Phone Settings
If you want your number hidden on every call without typing a prefix each time, both Android and iOS let you configure this at the system level.
On iPhone:
- Go to Settings → Phone → Show My Caller ID
- Toggle it off
On Android:
- Go to Phone app → Settings (three-dot menu) → Calls → Additional Settings → Caller ID
- Select Hide Number
The exact menu path varies by Android manufacturer and OS version — Samsung, Pixel, and OnePlus devices each organize these menus slightly differently.
Method 3: Carrier-Level Settings
Some carriers let you request a permanent caller ID block applied to your account, rather than managing it through your phone. This is sometimes called a Line Block and can be set up through your carrier's customer support or account portal.
The practical difference: a carrier-level block applies regardless of what device you use on that line, including older phones that might not have granular caller ID settings.
What Can Override Your Block 🔒
This is where it gets more nuanced. Blocking your number doesn't guarantee the recipient sees nothing useful. Several factors can affect what actually gets through:
| Scenario | What Happens |
|---|---|
| Calling emergency services (911, 999, etc.) | Your number is always delivered regardless of block |
| Calling a toll-free number (1-800, 1-888, etc.) | Many toll-free services use ANI (Automatic Number Identification), which bypasses caller ID suppression |
| Recipient uses a call-unmasking app | Some apps and services attempt to identify blocked callers |
| VoIP-to-VoIP calls | Behavior varies by platform and service provider |
| Business phone systems | Some PBX systems log or display technical call data the end user doesn't see |
The key distinction is between Caller ID and ANI. Caller ID is what gets displayed to the person picking up. ANI is a separate technical field used for billing and routing — and it's not suppressed by *67 or similar methods. Businesses that pay for ANI delivery (common in call centers and toll-free lines) can still see your number even when your caller ID is blocked.
How This Works Differently Across Devices and Carriers
The consistency of caller ID blocking depends on a few variables:
Carrier policies differ. Most major carriers in the US honor *67 suppression, but prepaid carriers and MVNOs (carriers that run on top of major networks) occasionally handle caller ID data differently.
VoIP apps and services — like Google Voice, WhatsApp calls, Skype, or FaceTime Audio — each manage caller ID independently. Google Voice, for example, already masks your real number by default when using a Voice number. Other apps may show a generic number or nothing at all, separate from your device settings.
International calls add another layer. *67 may not work when calling internationally, and the receiving country's network may handle suppression requests inconsistently.
Business phone systems and two-line apps (like apps that give you a second number on one phone) often have their own caller ID settings that sit on top of your device settings.
The Tradeoff Worth Knowing
Blocking your number improves outgoing privacy, but it also reduces the chance of your call being answered. Many people — and virtually all spam-filtering systems — automatically decline calls from blocked or unknown numbers. If you're trying to reach someone who doesn't have your number saved, a blocked call may go straight to voicemail or be ignored entirely.
Whether that tradeoff makes sense depends entirely on why you're blocking, who you're calling, and how your number reaches them given your specific carrier, device, and the services involved on both ends.