Check Out the Silence Unknown Callers Feature in iOS 13 for Blocking Spam Calls

Spam phone calls have become increasingly problematic in the United States over the course of the last few years, and most people receive multiple spam calls per week, and some, per day.

Apple is aiming to help combat spam phone calls in iOS 13 with a new "Silence Unknown Callers" feature, which does what the name suggests - it silences incoming phone calls from numbers that are not in your contacts list. In our latest YouTube video, we checked out this feature to demonstrate just how it works.


With the Silence Unknown Callers feature activated, all incoming calls to our test phone from unknown numbers (aka numbers not in our Contacts list) were silenced.

Silenced means sent straight to voicemail without the phone ringing at all, but the person does have the chance to leave a voice message. The person being blocked still hears the standard number of rings before voicemail picks up, so there's no real indication that Silence Unknown Callers is on.

For a call to come through with Silence Unknown Callers turned on, it needs to be added to the Contacts list. A number previously sent in an email (iOS can sometimes recognize phone numbers from emails) does not green light a call to go through. If you call a number that was sent straight to voicemail, however, it is no longer recognized as an unknown number even if that number isn't added to your contacts.

Silence Unknown Callers is a simple solution, but it's not identifying spam calls or risky numbers specifically. It's blocking out all unknown numbers, which may not always be a desirable solution. Still, those silenced callers can leave voicemails and the numbers are listed in the Recents list in the Phone app, so this is a solid way to cut down on calls that you don't want if you're contacted by a lot of spammers.

You can turn on the Silence Unknown Callers feature in iOS 13 by opening up the Settings app, selecting the Phone section, scrolling down to "Call Silencing and Blocked Contacts" and toggling the Silence Unknown Callers option to the on position.

Silence Unknown Callers is activated right now in both the iOS 13 developer and public betas, and it will be available for everyone with an iOS 13-compatible iPhone when iOS 13 launches this fall.

Related Forum: iOS 13

Popular Stories

Apple CarPlay Ultra instrument cluster themes 01

Apple's CarPlay Ultra Is Here – Does Your iPhone Support It?

Thursday May 15, 2025 5:17 am PDT by
Apple's recently announced CarPlay Ultra promises a deeply integrated in-car experience, but not all iPhone users will be able to take advantage of the new feature. According to Apple's press release, CarPlay Ultra requires an iPhone 12 or later running iOS 18.5 or later. This means if you're using an iPhone 11, iPhone XR, or any older model, you'll need to upgrade your device to access...
Apple CarPlay Ultra instrument cluster themes 01

Apple's 'CarPlay Ultra' Experience Now Available

Thursday May 15, 2025 5:07 am PDT by
Apple today announced that its next-generation CarPlay experience, now dubbed "CarPlay Ultra" begins rolling out today, starting with Aston Martin vehicles. Subscribe to the MacRumors YouTube channel for more videos. CarPlay Ultra is now available with new Aston Martin vehicle orders in the U.S. and Canada. It will also be available for existing models that feature the brand's next-generation ...
iPhone 17 Air Pastel Feature

iPhone 17 Air Battery Capacity and Weight Allegedly Revealed

Monday May 19, 2025 2:22 am PDT by
Apple is expected to launch an all-new ultra-thin iPhone 17 Air later this year, and while there have been plenty of rumors about the camera's overall design and thinness, we haven't heard any details about the device's weight and battery capacity until now. According to the leaker going by the account name "yeux1122" on the Korean-langauge Naver blog, the 6.6-inch iPhone 17 Air has a weight ...
CarPlay Ultra Climate Controls

Apple Says These Vehicle Brands Plan to Offer All-New CarPlay Ultra

Thursday May 15, 2025 8:13 am PDT by
Apple today announced the launch of CarPlay Ultra, the long-awaited next-generation version of its CarPlay software system for vehicles. CarPlay Ultra features deep integration with a vehicle's instrument cluster and systems, built-in Radio and Climate apps, customizable widgets, and more. The interface is tailored to each vehicle model and automaker's identity, and drivers can also adjust...
iOS 18 Siri Personal Context

Apple Will Reportedly Be More Cautious About Announcing New Features Well in Advance

Sunday May 18, 2025 2:50 pm PDT by
Apple plans to mostly stop announcing new features more than a few months before they are ready to launch, according to Bloomberg's Mark Gurman and Drake Bennett. The pair of reporters revealed this noteworthy tidbit towards the bottom of a lengthy report about Apple's artificial intelligence shortcomings today. This alleged change in strategy comes after Apple was forced to delay its more...
Apple Intelligence General Feature

Report: Apple's Next-Gen Version of Siri Is 'On Par' With ChatGPT

Monday May 19, 2025 9:00 am PDT by
Apple has big plans to improve Siri over the next few years, Bloomberg's Mark Gurman and Drake Bennett report. Some Apple executives are now reportedly pushing to turn Siri into a true ChatGPT competitor. A next-generation, chatbot version of Siri has reportedly made significant progress during testing over the past six months; some executives allegedly now see it as "on par" with recent...

Top Rated Comments

ViDeOmAnCiNi Avatar
76 months ago
this is not what I imagined this would be. I wanted blocks for calls that come up on callerid as "unknown", not to block the world except for what's in my contacts... Apple please try again.
Score: 46 Votes (Like | Disagree)
Small White Car Avatar
76 months ago
this is not what I imagined this would be. I wanted blocks for calls that come up on callerid as "unknown", not to block the world except for what's in my contacts... Apple please try again.
Ironically, the "unknown" callers are all things I want to answer these days. It tends to be a doctor or government office, usually.

Meanwhile, every spammer in the world has figured out how to spoof the area code next to mine so they appear to be local calls from the next town over.

Not sure that blocking 'unknown' would do a darned thing anymore. Spammers have moved on.
Score: 38 Votes (Like | Disagree)
PickUrPoison Avatar
76 months ago
this is not what I imagined this would be. I wanted blocks for calls that come up on callerid as "unknown", not to block the world except for what's in my contacts... Apple please try again.
No, blocking unknown is not very helpful, pretty much useless actually. Nearly all of my robocalls have caller ID, many times spoofed with my area code and sometimes a local prefix, or even my exact prefix. I rarely get a phone call that comes through as unknown/no caller ID.
Score: 18 Votes (Like | Disagree)
ugcop Avatar
76 months ago
It blocks any and all numbers NOT in your contact list. I have been using it from day one and have not had a single sales, give away, phishing Robo call of any kind. It sends everything not in contacts to voicemail with no ring on your end. In the weeks I have used it I only had two legitimate calls go to voicemail and they left messages. I then added them to contacts. I’m loving it.
Score: 13 Votes (Like | Disagree)
WilliamG Avatar
76 months ago
this is not what I imagined this would be. I wanted blocks for calls that come up on callerid as "unknown", not to block the world except for what's in my contacts... Apple please try again.
Agreed. I get calls from doctors or my vet or whatever, and they don't always call from the regular number listed for them. I know for myself - I'd never use this feature.
Score: 12 Votes (Like | Disagree)
Trik Avatar
76 months ago
This is a step in the right direction, but the Android Call Screening is really slick. If you haven't seen it...



One of the only features I envy on Android.
Score: 11 Votes (Like | Disagree)