The simplest way to stop anonymous calls

You can block calls from people who hide their number by turning on Silence Unknown Callers in your iPhone's Phone settings. This feature sends any call from a number not in your contacts straight to voicemail without ringing your phone. It is the fastest way to stop anonymous calls from interrupting you.

If you want to keep some unknown numbers able to reach you — for example, calls from your doctor's office or a delivery service — you can use a more selective approach instead. You can block individual callers after they call, or you can use a third-party app that gives you more control over which unknown numbers get through.

Key Takeaways

  • Silence Unknown Callers blocks all calls from numbers not in your contacts, sending them directly to voicemail without ringing your phone.
  • You can turn on Silence Unknown Callers in Settings > Phone > Silence Unknown Callers with just one toggle.
  • If you block all unknown callers, important calls from businesses or services may go to voicemail, so check your voicemail regularly.
  • You can block individual callers by opening a recent call and selecting Block This Caller, which works for both anonymous and known numbers.
  • Third-party apps like Nomorobo or Truecaller offer more detailed filtering if you want to block certain types of calls but allow others through.

Turn on Silence Unknown Callers in three steps

Open the Settings app on your home screen. Tap Phone, then scroll down and tap Silence Unknown Callers. Toggle the switch to the right so it turns green. That is all you need to do — from now on, calls from numbers not saved in your contacts will go straight to voicemail.

When this feature is on, your phone will not ring or vibrate for unknown callers. You will see a notification that a call came in, but it will not interrupt what you are doing. Check your voicemail later to see if the call was important. This is especially useful if you get many spam or scam calls during the day.

What happens to calls when you turn this on

Any call from a number you have not saved in your contacts will go directly to voicemail. The caller will hear your voicemail greeting and can leave a message. You will get a notification that a call came in, but your phone will not ring or vibrate. If the caller is someone you know, they can call back from a different number, or you can call them back after you see their voicemail.

Calls from people in your contacts will still ring normally, even if they are calling from an unknown number. For example, if your dentist's office calls from a number you have not saved, the call will go to voicemail. If your mother calls from a friend's phone, the call will ring because her name is in your contacts.

Block individual callers one at a time

If you do not want to block all unknown callers, you can block specific numbers after they call. Open the Phone app and go to Recents. Find the call you want to block, tap the i icon next to it, scroll down, and tap Block This Caller. Confirm by tapping Block Contact. That caller will never reach you again — their calls will go to voicemail and they will not see that you blocked them.

This approach takes more time if you get many unwanted calls, but it lets you keep your phone available for calls from unknown numbers you might need — like a hospital calling about test results, or a delivery driver trying to find your address. You can unblock a caller later by going to Settings > Phone > Blocked Contacts, finding the number, and tapping Edit, then Unblock.

Use a third-party app for more control

Apps like Nomorobo, Truecaller, and RoboKiller let you filter calls in more detail than the built-in iPhone tools. These apps can identify spam and scam calls before they reach you, show you the caller's name even if the number is hidden, and let you set rules for which types of calls to block. Some are free with limited features, and some charge a monthly fee for full protection.

To use a third-party app, read it from the App Store, open it, and follow the setup steps. Most will ask permission to access your contacts and call history. You can then set your preferences — for example, blocking all calls marked as spam but allowing calls from businesses. These apps work alongside Silence Unknown Callers, so you can use both at the same time.

Why anonymous calls happen and what scammers want

Callers hide their number for different reasons. Some are legitimate — hospitals, government offices, and large companies sometimes use blocked numbers for privacy. Many others are scammers trying to trick you into giving them money or personal information. They hide their number because they know you are less likely to answer if you see it is blocked.

Scammers often claim to be from your bank, the IRS, Apple, or a utility company. They create urgency by saying your account is compromised or you owe money. They want you to give them passwords, credit card numbers, or access to your computer. Hanging up and calling the real company directly using a number from their official website is always the safest response.

Check your voicemail so you do not miss important calls

When you turn on Silence Unknown Callers, legitimate callers from unknown numbers will leave voicemail messages. Check your voicemail regularly — at least once a day — so you do not miss calls from your doctor, your child's school, or a delivery service. Open the Phone app, tap Voicemail, and listen to messages in order from newest to oldest.

If you hear a voicemail from a caller you recognize or trust, you can call them back right away. If it is spam, you can delete it. Over time, you will learn which unknown numbers are safe to add to your contacts so their calls ring through in the future. For example, if your dentist's office calls regularly, save their number so you do not miss their calls.

Frequently Asked Questions

Will people know I blocked them?

No. When you block a caller, they will not receive a notification that you blocked them. Their call will go to voicemail as if your phone was off or you did not answer. They may eventually realize you are not responding, but they will not get a message saying you blocked them.

Can I block calls from a specific area code?

The built-in iPhone tools do not let you block entire area codes. However, third-party apps like Nomorobo and Truecaller can block calls from specific area codes or countries. You can also manually block numbers one at a time using the Phone app's Recents list.

What if I turn on Silence Unknown Callers and then change my mind?

Go back to Settings > Phone > Silence Unknown Callers and toggle the switch to the left so it turns gray. All unknown callers will ring your phone normally again. You can turn it back on at any time.

Do I need to pay for an app to block anonymous calls?

No. Silence Unknown Callers is free and built into every iPhone. Many third-party apps offer free versions with basic blocking, though they may show ads or limit features. Premium versions usually cost a few dollars per month.

Will blocking calls affect my voicemail?

No. Blocked callers can still leave voicemail messages. You will see their voicemail in your Voicemail tab, and you can listen to it, delete it, or call them back if you choose.