Silence Unknown Callers On iPhone

If your iPhone rings constantly with calls from numbers you do not recognize, there is a built-in setting that can help. It requires no third-party app, no subscription, and no ongoing maintenance.

It is called Silence Unknown Callers.

What it does

When enabled, any call from a number not in your contacts, recent calls, or Siri suggestions is automatically silenced. The call goes directly to voicemail. You will see a missed call notification, but your phone will not ring.

Legitimate callers who are not in your contacts can still leave a voicemail. Spam callers typically do not.

How to enable it

The location of this setting changed in iOS 18. Apple moved Phone into the Apps section of Settings.

1. Open Settings
2. Tap Apps
3. Tap Phone
4. Scroll down and tap Silence Unknown Callers
5. Toggle it on

If you are on an older version of iOS, the path is shorter: Settings then Phone then Silence Unknown Callers.

What to expect

You may miss the occasional legitimate call from an unknown number: a doctor’s office, a contractor, or a business you are dealing with. This is the tradeoff. Most people find it acceptable given the reduction in spam calls.

If you are expecting a call from an unknown number, you can temporarily disable the setting, then re-enable it afterward.

Why this matters

Spam calls are not just annoying. They are often the opening move in a social engineering attempt. Reducing your exposure to unsolicited calls is a simple and effective privacy measure.