How to Block Private Calls on Any Device

Receiving calls from hidden or blocked numbers is one of those modern frustrations that sits somewhere between annoying and genuinely unsettling. Whether you're dealing with persistent telemarketers, harassment, or simply prefer not to be interrupted by anonymous callers, blocking private calls is entirely possible — though how you do it depends heavily on your device, carrier, and how much control you want over the process.

What Is a "Private Call" and Why Can Callers Hide Their Number?

A private call (also called a blocked, unknown, or no-caller-ID call) happens when someone deliberately suppresses their outgoing caller ID before dialing. This is typically done by dialing *67 before a number in North America, which instructs the carrier to withhold the caller's number from the recipient's display.

Some callers — such as doctors' offices, law firms, or government agencies — use COID (Caller ID suppression) at the account level, meaning every outgoing call from their system appears private by default.

The challenge with blocking these calls is that there's no actual number to block. Instead of targeting a specific digit string, you're blocking a category of call.

Method 1: Ask Your Carrier to Block Anonymous Calls

The most reliable method is going directly to your mobile or landline carrier. Most major carriers offer a feature — sometimes free, sometimes part of a paid tier — that rejects calls where no caller ID information is transmitted.

Common carrier options include:

• AT&T: Anonymous Call Rejection via *77 (landlines) or through the ActiveArmor app (mobile)
• Verizon: Call Filter app, with anonymous call blocking in the premium tier
• T-Mobile: Scam Shield app, which includes an option to block calls with no caller ID
• Comcast/Xfinity: Anonymous call rejection available through account settings (landline)

The specifics of what's included for free versus paid vary by plan and change over time, so checking directly with your carrier gives you the most accurate picture of what's available to your account.

Method 2: Block Private Numbers on iPhone 📱

Apple doesn't offer a dedicated "block all unknown callers" toggle in the traditional sense, but iOS does include a feature called Silence Unknown Callers.

To enable it: Settings → Phone → Silence Unknown Callers → toggle On

When active, calls from numbers not in your contacts, recent outgoing calls, or Siri suggestions are automatically silenced and sent to voicemail. This includes most private or no-caller-ID calls.

Important distinction: This silences calls rather than outright rejecting them, so callers can still leave voicemail. If your goal is to prevent any contact, pairing this with a carrier-level block is more effective.

For users on iOS 13 and later, this feature is natively available. Older iOS versions may require a carrier-based solution instead.

Method 3: Block Private Numbers on Android

Android's approach varies significantly depending on the manufacturer and Android version. Stock Android (like on Pixel devices) and manufacturer skins (Samsung One UI, etc.) handle this differently.

On stock Android: Phone app → Settings → Blocked Numbers → toggle "Block calls from unidentified callers"

On Samsung devices: Phone app → More (three dots) → Settings → Block numbers → toggle "Block unknown callers"

Android's built-in options typically reject the call outright rather than silencing it, which is a meaningful difference if you want callers to receive a busy signal rather than reach voicemail.

Method 4: Third-Party Call-Blocking Apps

If your carrier's tools feel limited or your phone's native options don't go far enough, several third-party apps add more granular control:

Most of these apps work by integrating with your carrier's network or using your phone's built-in call-screening API. Their effectiveness depends on whether your carrier supports third-party integration and whether the app has the right permissions on your device.

Method 5: *77 — The Landline Anonymous Call Rejection Code 📞

If you're on a traditional landline or a VoIP service that supports it, dialing *77 activates anonymous call rejection at the network level. Callers with no caller ID hear an automated message telling them the recipient isn't accepting anonymous calls.

To deactivate it, dial *87.

This is one of the cleanest solutions available for landline users because it operates at the carrier network level, meaning it doesn't depend on your phone's settings or apps at all.

The Variables That Determine What Works for You

Here's where individual situations diverge considerably:

• Carrier: Not all carriers support the same features, and free versus paid tiers vary widely
• Device and OS version: iOS 13+ and modern Android builds have native options; older devices may not
• Call type: Are you trying to stop all unknown calls, or only calls that appear as "Private Number" specifically?
• Voicemail preference: Do you want callers to reach voicemail, or receive a rejection message?
• Use case: A home landline, a personal mobile, and a business phone each have meaningfully different requirements
• VoIP services: Services like Google Voice, Skype, or business PBX systems have their own call-handling rules that may override device-level settings

Someone using a carrier that bundles anonymous call rejection, on a current iPhone or Android, with no need to receive voicemails from unknown parties, has a very different set of options compared to someone on an older plan, a legacy landline, or a business VoIP system with shared extensions.

The right combination of carrier settings, device features, and potentially a third-party app depends entirely on how those factors line up in your specific situation. 🔍