How to Block Restricted Numbers: Ways to Stop Harassment and Scam Callers

You answer a call, and a voice claims to be a police officer. They warn of an outstanding warrant and demand payment. Panic sets in. But there’s a problem—the call came from a restricted number, hiding the caller’s identity.

This was the reality for residents of Friendswood, Texas, in a December 2024 scam where fraudsters posed as law enforcement, pressuring victims to pay using gift cards. The Friendswood Police Department issued a warning, urging people to avoid engaging with unknown callers.

Scam calls like these are common, and many rely on restricted calls to avoid detection. According to the Federal Communications Commission (FCC), billions of unwanted calls are blocked each year, yet many still get through, leaving people vulnerable to fraud, harassment, and unwanted solicitations.

If you’re receiving persistent restricted calls, there are ways to block them. This guide explains why restricted calls happen, how to block them on iPhone and Android, and additional ways to protect your privacy.

The good news is that you don’t have to tolerate unwanted restricted calls. Whether you’re dealing with persistent scammers, telemarketers, or harassment, there are several effective ways to block these calls.

Blocking restricted calls through your carrier

Many cell phone carriers offer call-blocking services that can prevent restricted numbers from reaching you, but availability depends on your provider and plan.

How to check if your carrier blocks restricted numbers

1. Log in to your carrier account via their website or mobile app.
2. Search for call-blocking options under settings. Look for terms like “Call Filter,” “Call Protect,” or “Block Restricted Calls.”
3. Contact customer support if no clear option is available. Some carriers offer restricted call blocking only with premium plans.

Some major carriers have names for their call-blocking services, including:

• Verizon: Call Filter (free and premium versions)
• AT&T: Call Protect
• T-Mobile: Scam Shield
• Sprint: Call Screener

If your carrier doesn’t offer full blocking, try built-in phone settings or third-party call-blocking apps for additional protection.

Using your device’s built-in settings

Most smartphones have built-in features that can help you manage restricted calls without needing additional apps or services. While the exact steps vary by device, these native options are often the quickest way to reduce unwanted calls.

For iPhone

Apple does not offer a direct option to block restricted numbers specifically, but there is an effective workaround using a built-in iOS feature.

The Silence Unknown Callers feature sends calls from unknown numbers—including restricted calls—directly to voicemail. Your iPhone won’t ring, but you can still see the call in your Recents list.

How to enable Silence Unknown Callers on iPhone:

1. Open Settings on your iPhone.
2. Scroll down and tap Apps.
3. Tap Phone.
4. Tap Silence Unknown Callers.
5. Toggle Silence Unknown Callers to on (green).

Fig 1. Enabling Silence Unknown Callers on iPhone

For Android

Most Android phones let you block unknown or private numbers in the Phone app settings.

The steps can vary between manufacturers but here’s what to do on most devices:

1. Open the phone app and go to Settings.
2. Tap Block numbers.
3. Enable Block calls from unknown numbers.

Fig 2. Blocking calls from unknown numbers on Android

Keep in mind:

• Some Android devices only silence restricted calls instead of blocking them outright. Try carrier-level blocking or a third-party app if your phone lacks this option.
• Google Pixel phones don’t have a separate “Restricted Numbers” block option—this setting will block calls from all unknown numbers, which may include legitimate ones.
• Not all Android devices have a setting to block unknown numbers. If your phone doesn’t offer it, try carrier-level blocking (see previous section) or use a third-party call blocker.

Using a third-party app for call blocking

If your carrier doesn’t support blocking restricted calls, or if changing your device settings doesn’t fully solve the problem, third-party apps can help.

Popular call-blocking apps that work on iPhone and Android

How to set up a call-blocking app

1. Download the app from Apple’s App Store or Google’s Play Store.
2. Open the app and follow the setup instructions.
3. Grant the app permission to manage calls and block numbers.
4. In the app settings, enable “Block Restricted Calls” or a similar feature.

Using Do Not Disturb (DND) to block restricted calls

Do Not Disturb (DND) is a built-in feature on iPhone and Android that allows you to silence incoming calls except those from specific people. This is an effective way to stop restricted calls while still allowing calls from people you know.

How to enable Do Not Disturb on iPhone

1. Swipe down from the top right of your screen to open the Control Centre.
2. Tap the Focus button and choose Do Not Disturb.
3. To control which calls can still reach you when Do Not Disturb is enabled, go to Settings > Focus > Do Not Disturb > People.

How to enable Do Not Disturb on Android

1. Swipe down from the top of the screen.
2. Tap Do Not Disturb (or Modes > Do Not Disturb on some models).
3. To control which calls can still reach you when Do Not Disturb is enabled, go to Settings > Notifications (or Modes on some models) > Do Not Disturb > Calls and messages.

Using VoIP services to filter restricted phone calls

VoIP (Voice over Internet Protocol) services like Google Voice, Microsoft Teams, or OpenPhone offer advanced call filtering that many carriers don’t. If you use a VoIP number, you can set up call screening to block restricted phone calls automatically.

How to block restricted numbers with Google Voice

1. Download and install Google Voice from the Google Play Store or App Store.
2. Open the app and sign in with your Google account.
3. Tap the menu icon (☰) and go to Settings.
4. Scroll down to Filter spam calls and toggle it on.
5. Google Voice will now automatically detect and block restricted calls before they reach your phone.

Call forwarding restricted numbers to a dead line

Some users have successfully redirected restricted calls to an unassigned number, preventing them from reaching their phone.

How to forward restricted calls to an unassigned number:

1. Find an inactive or disconnected number (e.g., a non-working VoIP line).
2. Contact your carrier and request conditional call forwarding for restricted phone calls.
3. Provide the unassigned number as the forwarding destination.
4. Now, whenever a restricted call comes in, it will be forwarded to a dead line instead of reaching you.

Privacy and Security Risks of Restricted Calls

Restricted calls aren’t just an annoyance—they can be a tool for scammers, harassers, and cybercriminals.

Since these calls hide caller IDs, they make it easier for fraudsters to impersonate law enforcement, tech support, or financial institutions, pressuring victims into giving up money or personal information.

What to do if a restricted caller is harassing you

If you receive repetitive restricted calls that feel threatening or harassing, take these steps:

1. Keep a record: Note the date, time, and frequency of restricted calls.
2. Report the harassment: Contact your phone carrier to see if they can trace the number. In severe cases, file a report with local authorities.
3. Consider legal action: In some regions, persistent anonymous calls can be considered harassment and may be legally actionable.
4. Use call-blocking measures: Use the methods described earlier in this article to reduce unwanted calls.

Some restricted calls still get through

Even if you enable call blocking on your phone, through your carrier, or via third-party apps, some restricted calls may still bypass these filters. This can happen because:

• Some restricted calls are routed through VoIP or spoofing techniques, making them appear as legitimate numbers.
• Calls from emergency services, government agencies, or hospitals that use restricted numbers may still get through.
• Carriers have different call-blocking policies—some providers allow blocking restricted calls at the network level, while others do not.

Best Practices for Blocking Restricted Numbers

Blocking restricted numbers reduces spam, scams, and unwanted calls, but no method is foolproof. The best results come from combining multiple approaches:

• Use built-in phone settings like Do Not Disturb or Silence Unknown Callers to limit disturbances.
• Enable carrier-level blocking if your provider offers services like Call Filter or Scam Shield.
• Consider VoIP filtering for advanced call control.
• Try not to answer restricted calls. It tells the caller that the number is active and their calls may become more frequent.
• Let unknown numbers go to voicemail to avoid missing important calls while filtering out unwanted ones.

Wrapping Up

Restricted calls have become a tool for those who want to reach you without accountability. While blocking them can improve privacy and security, it’s important to strike the right balance. Relying solely on phone settings may not be enough, and blocking all unknown calls could mean missing something important.

Instead, the best approach is proactive call management. Using carrier-level blocking, VoIP filtering, or third-party apps alongside built-in features offers the most control. If restricted calls persist in a targeted pattern, consider whether there’s a larger security issue at play.