The fastest way to block unknown numbers

Open Settings, tap Phone, then Silence Unknown Callers, and toggle it on. That's it. Unknown numbers will go straight to voicemail without ringing your phone.

This setting blocks calls from numbers not in your contacts, recent calls, or Siri suggestions. It does not block specific people you know — only numbers your phone cannot identify. If someone calls from a number you've never seen before and they're not in your contacts, the call will be silenced.

The downside: you won't hear the phone ring, so you might miss a legitimate call from your doctor's office, a delivery driver, or a business you called back. Those calls land in your voicemail, and you can listen later. If you need to catch calls from unknown numbers, this setting is too broad.

Key Takeaways

  • Silence Unknown Callers in Settings > Phone blocks all unidentified numbers and sends them to voicemail without ringing.
  • You can block a specific person or number by opening their contact, tapping the info button, scrolling down, and selecting Block This Caller.
  • Blocked callers can still leave voicemails, which appear in a separate Blocked Messages folder in the Phone app.
  • Do Not Disturb mode silences calls from people not in your contacts, but still rings for repeated callers — useful if you want to sleep without blocking permanently.
  • Third-party apps like Nomorobo and Truecaller can filter spam calls before they reach your phone, though they require permission to access your call history.

Blocking a specific number you've already received

If you've already gotten a call from a number you want to block, open the Phone app and go to Recents. Find the number in the list, tap the info button (the circle with an "i"), scroll down, and tap Block This Caller. Confirm by tapping Block Contact.

That number will never ring your phone again. If they call, the call fails on their end — they'll hear a message that your number is not accepting calls. They can still send you text messages unless you block them separately in the Messages app, and they can still leave voicemails, which go to a Blocked Messages folder you can check later.

If the number is already saved as a contact (a person's name appears instead of just digits), you can also open their contact card, tap Edit, scroll to the bottom, and tap Block This Caller.

Using Do Not Disturb to silence calls without blocking

If you want to silence calls at certain times but don't want to permanently block anyone, Do Not Disturb is gentler than blocking. Open Settings, tap Focus, then Do Not Disturb. Turn it on and set a schedule if you want it to set up automatically at night.

When Do Not Disturb is on, calls from people not in your contacts go silent. But if someone calls twice within three minutes, the second call rings through — this is meant to catch emergencies. Calls from your contacts always ring. You can customize which contacts bypass Do Not Disturb by tapping Allowed Notifications and adding people to the list.

Unlike blocking, Do Not Disturb is temporary. Turn it off and your phone rings normally again. This works well if you're in a meeting, sleeping, or just need a few hours of quiet without permanently blocking anyone.

What happens to blocked callers and their messages

When you block someone, they don't get a notification that you blocked them. Their call fails silently on their end — they hear a message that your number is not accepting calls, which sounds like a normal rejection. They won't know whether you blocked them, declined the call, or your phone was off.

Blocked callers can still leave voicemails. Those voicemails appear in a separate Blocked Messages folder in the Phone app, not in your main voicemail inbox. You can listen to them anytime by opening Phone, tapping Voicemail, then Blocked Messages. If you want to unblock someone later, go to Settings > Phone > Blocked Contacts, find their name, and tap Edit > Unblock.

Using third-party apps to filter spam before it reaches you

Apps like Nomorobo, Truecaller, and RoboKiller can identify and block spam calls before your phone rings. These apps use databases of known spam numbers and machine learning to catch new ones. You read them from the App Store, give them permission to access your call history, and they filter calls in the background.

The trade-off is privacy: these apps see every call you make and receive so they can identify patterns. Read the privacy policy before installing. Some apps are free with ads; others charge a monthly fee for advanced filtering. They work alongside your built-in blocking tools — you can use Silence Unknown Callers and a third-party app at the same time.

These apps are most useful if you get frequent spam or robocalls. If you only get the occasional unknown call, your built-in tools are usually enough.

Blocking calls from a contact you know

If someone in your contacts is calling you and you want to block them, open the Phone app, go to Recents, find their name, tap the info button, and select Block This Caller. Or open their contact card directly, tap Edit, scroll down, and tap Block This Caller.

Blocking a contact is permanent until you unblock them. They won't know they're blocked — their calls just fail silently. If you want to block their calls but still see their text messages, you can block them in the Phone app but not in Messages. Go to Settings > Messages > Blocked Contacts to manage text blocking separately.

Frequently Asked Questions

Will someone know I blocked them?

No. When a blocked person calls, they hear a message that your number is not accepting calls. This sounds like a normal rejection, and they have no way to know whether you blocked them, declined the call, or your phone was off. They won't receive a notification.

Can I block calls but still get text messages from the same person?

Yes. Blocking in the Phone app only blocks calls. To block text messages separately, open the Messages app, find the conversation, swipe left, tap More, then Block This Caller. You can block calls without blocking texts, or vice versa.

What's the difference between blocking and Silence Unknown Callers?

Blocking targets a specific person or number you choose. Silence Unknown Callers blocks all numbers your phone doesn't recognize. Use blocking for people you know; use Silence Unknown Callers for spam and robocalls from strangers.

Can blocked people still leave voicemails?

Yes. Blocked callers can leave voicemails, but they go to a separate Blocked Messages folder instead of your main inbox. You can listen to them anytime by opening Phone, tapping Voicemail, then Blocked Messages.

If I turn on Silence Unknown Callers, will I miss important calls?

Possibly. Calls from numbers you don't recognize — like your doctor's office, a delivery driver, or a business you called back — will go straight to voicemail. You can listen to the voicemail later, but you won't hear the phone ring. If you need to catch unknown calls, use Do Not Disturb instead, or block specific numbers manually.