How to Block Caller ID and Make a Blocked Call from Any Number

Making a call where your number doesn't appear on the recipient's screen is a genuinely useful feature — whether you're returning a call to an unknown number, contacting someone through a classified ad, or simply prefer to keep your personal number private in certain situations. This is commonly called blocking your caller ID, and it's built into most phones and carrier services by default.

Here's how it works, what affects it, and why results vary depending on your setup.

What "Blocking" Your Number Actually Means

When you make a phone call, your carrier transmits your Caller ID — the number associated with your account — to the recipient's phone. Blocking your caller ID suppresses this transmission, so the receiving end sees "No Caller ID," "Private," "Unknown," or "Blocked" instead of your actual number.

This is different from blocking someone else's calls (which is about rejecting incoming calls). Blocking your own number is about controlling what information you broadcast outward.

Two main methods exist:

• Per-call blocking — You suppress your number for a single call only
• Permanent blocking — Your carrier hides your number on every outgoing call by default

How to Block Your Number on a Single Call 📞

The most universal method works on virtually every phone network in the US, Canada, and many other countries: dial *67 before the number.

Format:*67 + area code + phone number

Example:*67 555 867 5309

The call connects normally. Your number appears as "Private" or "No Caller ID" on the other end. This prefix code works on both landlines and cell phones, and costs nothing — it uses a standard carrier feature called Caller ID suppression.

In some other countries, the equivalent prefix differs:

Always verify the code for your specific country if you're outside North America.

Enabling Permanent Caller ID Blocking

If you want your number hidden on every call by default, most carriers let you request this at the account level. The process typically involves:

• Calling your carrier's customer support directly
• Logging into your account online and adjusting privacy or caller ID settings
• Visiting a carrier store

Once permanent blocking is active, your number is suppressed on all outgoing calls unless you reverse it for a specific call using *82, which temporarily unblocks your number for one call at a time.

How to Block Your Number on iPhone

On iOS, the option is built into Settings:

Settings → Phone → Show My Caller ID → toggle Off

When disabled, your number is hidden on all outgoing calls. You can toggle it back on at any time. This works over your cellular connection — if you're making calls through a third-party VoIP app (like WhatsApp or FaceTime), the caller ID behavior is controlled by those apps independently, not this system setting.

How to Block Your Number on Android 🤖

Android varies more by manufacturer and carrier, but the general path is:

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

Some carriers disable or override this menu option entirely, meaning you may need to contact your carrier directly to enable permanent blocking.

Important Variables That Affect How This Works

Not all blocked calls behave identically at the receiving end. Several factors determine what actually happens:

Carrier-to-carrier behavior: Some carriers or VoIP providers don't pass suppression signals consistently, especially in international calls. A number blocked from your end may still appear at the destination depending on the receiving carrier's infrastructure.

Call screening services: Many users and businesses now use call-screening apps or services (like Google's built-in Call Screen, or third-party apps) that automatically reject or flag calls from unknown numbers. A blocked call may go straight to voicemail, get an automated screening prompt, or be silently declined. This is increasingly common.

VoIP and app-based calls: Services like Google Voice, WhatsApp, Skype, and similar platforms manage caller ID through their own systems. The *67 prefix typically doesn't function within these apps. Each platform has its own privacy settings for outgoing caller ID.

Emergency services exception:*67 does not block your number from 911 (or equivalent emergency services). Emergency dispatch systems bypass caller ID suppression entirely. This is a legal requirement, not a technical limitation you can work around.

Business lines: Corporate phone systems often use PBX or VoIP setups that strip or alter caller ID information anyway. If you're calling from a work line, the behavior depends entirely on how that system is configured.

What Recipients Experience — and Why It Matters

Understanding the recipient's experience helps set realistic expectations. When your number is blocked:

• Phones display "No Caller ID," "Unknown," "Private," or "Blocked" — wording varies by device and carrier
• Many people simply don't answer calls from unidentified numbers
• Voicemail is typically still accessible
• Some carriers and apps offer Anonymous Call Rejection (often *77 on landlines), which automatically declines all private-number calls

This last point is significant. The more widespread call-blocking tools become, the less reliable a blocked call is as a practical communication method with people who don't know to expect it.

The Part That Depends on Your Situation

The technical process of blocking your caller ID is straightforward — *67 handles most cases instantly, and device or carrier settings cover the rest. But whether it achieves what you need depends heavily on your specific setup: which type of phone and carrier you use, whether you're making calls through native dialers or third-party apps, and what the person on the receiving end has configured on their end.

Someone using a standard cellular line calling another standard cellular line in the same country is in a very different situation than someone trying to suppress caller ID through a VoIP app to a business number that uses automatic unknown-call screening. Same goal, meaningfully different outcomes.