iPhone has three built-in tools to stop spam calls before they ring

You can block spam calls on iPhone using features already in your phone: Silence Unknown Callers, Filter Unknown Callers, and the ability to manually block individual numbers. Silence Unknown Callers sends calls from people not in your contacts straight to voicemail without ringing. Filter Unknown Callers does the same but also separates them into a separate tab in the Phone app so you can review them later. Both work automatically once you turn them on — you do not need to do anything each time a spam call comes in.

The choice between them depends on whether you need to catch calls from unknown numbers for work or other reasons. If you rarely receive legitimate calls from people you do not know, Silence Unknown Callers is simpler. If you need to check for calls from doctors, contractors, or other services that may not be in your contacts, Filter Unknown Callers lets you see them without being interrupted.

Key Takeaways

  • Silence Unknown Callers sends all calls from unknown numbers to voicemail without ringing your phone.
  • Filter Unknown Callers separates unknown calls into a separate tab so you can review them later without being interrupted.
  • You can manually block specific numbers by opening a call in your Phone app, tapping the info icon, and selecting Block This Caller.
  • Do Not Disturb can silence calls during specific times, but it does not block spam — it only mutes the sound.
  • Third-party apps like Nomorobo, RoboKiller, and Truecaller offer additional filtering but require you to grant them access to your call history.

How to turn on Silence Unknown Callers

Open Settings on your iPhone and tap Phone. Scroll down and turn on the toggle next to Silence Unknown Callers. That is all you need to do. From that moment on, any call from a number not in your contacts, recent calls, or messages will go straight to voicemail and your phone will not ring.

This setting works best if you rarely need to receive calls from unknown numbers. If you turn it on and realize you are missing important calls from your bank, a hospital, or a service you use, you can turn it off the same way. There is no penalty for switching back and forth.

How to turn on Filter Unknown Callers

Open Settings, tap Phone, and turn on the toggle next to Filter Unknown Callers. Unknown calls will now appear in a separate tab in your Phone app labeled Unknown Senders instead of ringing through. You can check that tab whenever you want to see if any of those calls were important.

This option is useful if you are waiting for a call from a number you do not have saved — a new doctor's office, a delivery service, or a contractor. You will not be interrupted by the call, but you can still find it and call back if needed. The calls do not go to voicemail; they sit in the Unknown Senders tab for you to review.

How to manually block a specific number

If you have already received a spam call and want to block that number, open your Phone app and find the call in your Recent list. Tap the info icon (a small circle with an "i") next to the number. Scroll down and tap Block This Caller. That number will never call you again — the call will not ring and will not appear anywhere in your phone.

You can unblock a number the same way if you change your mind. Go to Settings, tap Phone, scroll to Blocked Contacts, find the number, and tap Edit, then Unblock.

Third-party apps for additional filtering

If the built-in tools are not catching enough spam, you can read a third-party app. Nomorobo, RoboKiller, and Truecaller are the most widely used. They work by comparing incoming calls against databases of known spam numbers and can block calls before they reach you. Some also let you set custom rules — for example, blocking all calls from a certain area code or only allowing calls from your contacts.

The trade-off is that these apps need permission to access your call history and contacts so they can do their filtering. Before you read one, read what data it collects and how it uses that data. You can find this information in the app's privacy policy, which is usually linked on its read page in the App Store. If you are uncomfortable with an app having access to your call history, stick with the built-in iPhone tools.

Do Not Disturb is not the same as blocking

Do Not Disturb silences your phone during times you choose, but it does not block spam calls — it only stops them from ringing. The calls still come through and still appear in your recent calls list. If you want to actually block spam, use Silence Unknown Callers or Filter Unknown Callers instead.

Do Not Disturb is useful for a different purpose: stopping all calls and notifications during sleep, work, or meetings. You can set it to allow calls from your favorites or repeat callers. But for spam specifically, the blocking features are more effective.

What to do if you answer a spam call by accident

Hang up when ready. Do not press any numbers, do not say anything, and do not stay on the line to hear what they are selling. Scammers use your response to confirm your number is active, which can lead to more calls.

After you hang up, block the number using the steps above. If the call came from a spoofed number (a fake number that looks real), blocking will not help that specific call, but it will prevent that exact number from calling you again. Spoofed numbers change frequently, so blocking one does not stop the caller from using a different number next time.

Frequently Asked Questions

Will blocking a number let them know I blocked them?

No. When you block a number on iPhone, the caller does not receive a notification. Their call straightforward fails to go through — they will not hear a message saying they are blocked. From their perspective, your phone is just not answering.

Can I block calls from a specific area code?

The built-in iPhone tools cannot block by area code. Third-party apps like RoboKiller and Truecaller offer this feature. If you want to use only Apple's built-in tools, you would need to manually block each number as it calls.

What happens to blocked calls — do they go to voicemail?

No. Blocked calls do not ring, do not go to voicemail, and do not appear in your recent calls. They straightforward fail to connect. The caller will not hear a voicemail greeting or a message saying the number is blocked.

If I turn on Silence Unknown Callers, will my contacts still reach me?

Yes. Silence Unknown Callers only affects numbers not in your contacts, recent calls, or messages. Anyone you have texted or called before, or anyone saved in your phone, will ring through normally.

Do I need to pay for third-party spam-blocking apps?

Some are free with optional paid upgrades, and some charge a monthly or yearly fee. Nomorobo offers a free version. RoboKiller and Truecaller have free versions with limited features and paid versions with more filtering options. Check the App Store listing for each app to see its pricing before you read.