How to Block Your Phone Number When Making a Call

Hiding your number before dialing is one of those features most people don't know they have — until they need it. Whether you're calling a business you'd rather not hear back from, protecting your privacy on a classified ad, or simply keeping your personal number off someone's caller ID, blocking your number is built into virtually every phone and carrier plan. Here's how it works, what affects it, and where the method that's right for you depends entirely on your situation.

What "Blocking Your Number" Actually Means

When you make a standard call, your phone transmits your number as Caller ID data — a signal sent alongside the call that lets the recipient's phone display who's calling. Blocking your number instructs the network to suppress that data, so the recipient sees "No Caller ID," "Private Number," or "Unknown" instead of your digits.

This is handled at the network level, not just the app level, which is why it works even on basic calls from older phones. The suppression request travels with the call through the carrier's infrastructure.

It's worth knowing: emergency services (911 in the US) can always see your number, regardless of whether it's blocked. Certain businesses and government lines also have the ability to override caller ID blocking through services like "Trap and Trace." So this isn't invisibility — it's selective privacy.

The Three Main Methods for Blocking Your Number

1. Per-Call Blocking with a Prefix Code 📞

The simplest method requires no settings changes at all. Before dialing any number, enter:

• *67 (United States, Canada, most of North America)
• 141 (United Kingdom)
• #31# (many European and international networks)

So instead of dialing 555-123-4567, you'd dial *67-555-123-4567. Your number is hidden for that call only. The next call goes out normally.

This works on smartphones and landlines alike and doesn't require any app or account setting. It's the go-to for one-off situations where you want privacy without changing anything permanently.

2. Permanent Caller ID Blocking (Default Hidden)

If you want your number hidden on every call by default, you can flip a setting at the device or carrier level.

On iPhone: Settings → Phone → Show My Caller ID → toggle off

On Android: Phone app → Settings → Calls → Additional Settings → Caller ID → Hide Number (Menu paths vary slightly by manufacturer and Android version)

Through your carrier: Most carriers allow you to request permanent caller ID suppression on your account — sometimes through their app, online account portal, or by calling customer service. This applies network-wide, even if you switch devices.

Once enabled permanently, you can unblock on a per-call basis by dialing *82 before the number in the US. This reverses the permanent suppression for that one call.

3. Using a Third-Party App or Second Number

Apps like Google Voice, Burner, or similar second-number services give you a separate number to call from entirely. The recipient sees that number, not your real one. This approach goes beyond caller ID blocking — it creates a genuine layer of separation between your personal number and the call.

This is a meaningfully different method: you're not suppressing your number, you're calling from a different one. Useful for ongoing situations like selling items online, dating apps, or business use where you want a consistent alternate identity rather than just occasional privacy.

Factors That Affect Which Method Works for You

Not every method works the same way in every situation. A few variables matter:

The Difference Between "Hidden" and "Anonymous" 🔒

It's easy to conflate these, but they're not the same thing. Hiding your caller ID means the person you're calling doesn't see your number. Your carrier, the recipient's carrier, and law enforcement with proper authority still have access to call records. If you're thinking about this from a privacy standpoint, it's worth understanding that caller ID suppression is about social privacy, not technical anonymity.

For deeper separation — like keeping your number off data broker lists or preventing call-back marketing — the second-number app approach handles a different problem than *67 does.

What Changes Between iOS, Android, and Carriers

On iOS, the Show My Caller ID toggle is clean and straightforward, but some carriers override it — meaning even if you turn it off, your carrier's settings may take precedence. Checking with your carrier confirms whether the device toggle actually has effect.

On Android, the path to the Caller ID setting varies noticeably between manufacturers. Samsung's One UI, stock Android, and other skins place it in different menus. If you can't find it, searching "Caller ID" in your phone's Settings search bar usually surfaces it directly.

On carrier-managed plans — especially postpaid accounts — permanent suppression is often something customer service enables on the account itself, independent of the device. If you switch phones, the suppression follows the SIM and account, not the handset.

When the Method That Fits Depends on Your Setup

A one-time private call to a stranger is a different situation than running a small business from your personal phone. Blocking per-call with *67 is frictionless for occasional use. Permanent suppression makes sense if you almost never want your number displayed. A second number through an app fits a different profile entirely — someone who wants a dedicated, reusable alternate identity for calls.

Which of those matches your situation, how often you need it, and whether you're dealing with standard cellular calls or VoIP apps are the variables that make one approach a much better fit than the others.