Block Unknown Callers on iPhone & Android

This guide shows you how to stop spam, robocalls, and unknown numbers from ringing your iPhone or Android phone. You’ll learn the built-in settings for both platforms, plus a few extra steps to make the filtering even stronger. No apps or special skills are needed—just a few minutes in your phone’s settings.

What You’ll Need

• An iPhone running iOS 13 or later, or an Android phone running Android 6 or later (steps may vary slightly by manufacturer).
• Your phone’s passcode or biometric unlock, as some steps require access to Phone and Settings apps.
• Optional: A carrier that supports spam call labeling (most major carriers do).

Step-by-Step

On iPhone (iOS)

1. Open the Settings app (the gray gear icon).
2. Scroll down and tap Phone.
3. Tap Silence Unknown Callers.
4. Toggle the switch to On (it will turn green). This sends calls from numbers not in your Contacts, Recents, or Siri Suggestions to voicemail. They won’t ring your phone.
5. Optional: To also block specific numbers, go back to the Phone settings and tap Blocked Contacts, then tap Add New… and choose from your contacts or enter a number manually.

On Android (Stock/Google Pixel)

1. Open the Phone app (the dialer icon).
2. Tap the three-dot menu (⋮) in the top-right corner.
3. Select Settings.
4. Tap Caller ID & spam (or Spam and Call Screen on some devices).
5. Turn on See caller and spam ID (this helps identify spam calls).
6. Turn on Filter spam calls (this automatically blocks suspected spam calls).
7. Optional: To block a specific number, go back to the Phone app, tap the number in your Recents, then tap Block/report spam.

On Samsung Galaxy (One UI)

1. Open the Phone app.
2. Tap the three-dot menu (⋮) and select Settings.
3. Tap Caller ID and spam protection.
4. Toggle on Caller ID and spam protection (this enables spam detection).
5. Toggle on Block spam and scam calls (this automatically blocks suspected spam).
6. Optional: To block a specific number, go to Recents, tap the number, then tap Block.

On Other Android Phones (e.g., OnePlus, Xiaomi)

1. Open the Phone app.
2. Tap the three-dot menu (⋮) or the gear icon.
3. Look for Blocking, Spam protection, or Caller ID—the exact wording varies.
4. Enable any option that says Block unknown/private numbers or Filter spam calls.
5. If you can’t find it, search your settings for “block unknown” or “spam” using the search bar at the top of the Settings app.

Common Mistakes

• Not updating your phone: Older iOS and Android versions may not have these exact options. Update your phone to the latest software first.
• Assuming it blocks all unknown numbers: On iPhone, “Silence Unknown Callers” sends them to voicemail—it doesn’t hang up. On Android, “Filter spam calls” only blocks numbers that are flagged as spam, not every number not in your contacts.
• Forgetting that legitimate calls can be affected: Delivery drivers, doctors’ offices, or schools often call from unknown numbers. You may miss those calls.
• Not checking voicemail: Blocked calls may still leave voicemail. If you don’t check it, you might miss important messages.
• Blocking the wrong number: On Android, if you block a number from your Recents, you might accidentally block a number you actually want to hear from. Double-check before confirming.

Tips

• Use Do Not Disturb for extra control: On both platforms, you can set Do Not Disturb to allow calls only from your contacts, and schedule it for specific times (like at night).
• Report spam calls: When you get a spam call, report it to your carrier (e.g., by forwarding to 7726 on many carriers). This helps improve spam databases.
• Add important numbers to contacts: If you’re expecting a call from a new doctor or a delivery service, add their number to your contacts temporarily so it rings through.
• Use a third-party spam-blocking app (optional): Apps like Hiya or Truecaller can provide more aggressive filtering, but they require access to your call logs and may have subscription fees. The built-in options are usually enough for most people.
• Check your carrier’s spam-blocking features: Many carriers offer free call-blocking tools (e.g., AT&T Call Protect, Verizon Call Filter, T-Mobile Scam Shield). These can block more numbers than your phone alone.

Troubleshooting

• I still get spam calls after enabling the setting: The built-in filters are not perfect. Make sure you’ve also enabled your carrier’s spam-blocking feature (check their app or website). If you’re on iPhone, confirm that “Silence Unknown Callers” is actually on—go back to Settings > Phone and check the toggle. On Android, ensure “Filter spam calls” is on, not just “Caller ID”.
• I can’t find the setting on my Android phone: Manufacturers use different names. Search your Settings app for “spam”, “block”, or “caller ID”. If you still can’t find it, your phone’s software may be outdated—check for system updates in Settings > System > System update.
• Legitimate calls are going to voicemail: This is expected with “Silence Unknown Callers” on iPhone. To allow a specific number through, add it to your contacts. On Android, if you’re using “Filter spam calls”, only spam-flagged numbers are blocked, so if a legitimate call is blocked, it was incorrectly flagged—you can unblock it from the call log.
• Blocked numbers still ring: On iPhone, if a blocked number is in your Contacts (even if you blocked it later), it may still ring. Delete the contact or unblock and re-block it. On Android, ensure you’ve blocked the correct number format (e.g., with or without country code).
• I want to unblock a number: On iPhone, go to Settings > Phone > Blocked Contacts, swipe left on the number, and tap Unblock. On Android, go to the Phone app > Recents, tap the number, and select Unblock or Remove from blocked list.

Frequently Asked Questions

Will blocking unknown callers stop all spam calls?

No. It will stop most, but some spam calls can still get through, especially if the caller spoofs a number that looks like a legitimate one. Combining your phone’s settings with your carrier’s spam-blocking service gives the best results.

Does “Silence Unknown Callers” on iPhone block calls from numbers I’ve emailed?

No. It only allows calls from numbers in your Contacts, Recents, and Siri Suggestions. If you’ve emailed someone but never called them, their number is not automatically allowed.

Can I still see missed calls from blocked numbers?

Yes. On iPhone, blocked calls appear in your Recents list with a note that they were silenced. On Android, blocked calls may appear in your call log with a “Blocked” label, depending on your phone.

Will blocking unknown callers affect emergency calls?

No. Emergency numbers (like 911 in the US) are never blocked on any phone. You can always call emergency services.

Do I need to pay for a spam-blocking app?

No. The built-in features on both iPhone and Android are free. Carrier-provided spam-blocking services are also usually free, though some may have premium tiers. Paid apps are optional and not necessary for basic protection.

How do I block a specific number that keeps calling me?

On iPhone, go to the Phone app > Recents, tap the “i” next to the number, then tap “Block this Caller”. On Android, in the Phone app, tap the number in Recents, then tap “Block/report spam” (or similar). The number will be blocked immediately.

Related

• Computer Restarted Because of a Problem? Fix It
• Fix BitLocker Error 0x80072f9a on Windows
• Sony Noise-Canceling Headphones: Pairing Guide