Check Out the Silence Unknown Callers Feature in iOS 13 for Blocking Spam Calls - MacRumors
Skip to Content

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

M5 MacBook Pro

RIP, MacBook Ultra

Monday October 19, 2026 9:37 am PDT by
Apple today sent out invites for an experience in Los Angeles on Wednesday, October 28, and the "Pro and tell" tagline on the invitation likely means that the rumored MacBook models with touch-enabled OLED displays will stick with MacBook Pro branding instead of the once-rumored "MacBook Ultra" name. The long-rumored "iPhone Ultra" ended up being named iPhone Duo, so speculation that Apple...
iPhone Duo Trio

Here's What Apple's Apps Look Like on the iPhone Duo

Tuesday October 20, 2026 11:12 am PDT by
With just three days to go until the iPhone Duo is released, Apple is getting ready for the launch. Behind the scenes, the App Store now has screenshots of Apple's built-in apps running on the Duo. We've seen some apps in marketing materials, but images of the ones we haven't seen give us an idea of what it will be like using the iPhone Duo day to day. Many apps are shown in landscape...
apple pro tell logo

Apple Announcing New Products Next Week: 'Pro and Tell'

Monday October 19, 2026 9:05 am PDT by
Apple's Greg Joswiak today hinted at new product announcements coming next week, sharing a social media post that says "Can't wait to pro and tell next week." Rumors suggest Apple is planning to debut the new MacBook Pro with an OLED touchscreen display, an M6 entry-level MacBook Pro, an M6 iMac, an iPad mini with an OLED display. Can't wait to pro and tell next week....

Top Rated Comments

ViDeOmAnCiNi Avatar
94 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
94 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
94 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
94 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)
94 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)
94 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)
Latest Stories
Things Updated for iPhone Duo With Adaptive Layout
Things Updated for iPhone Duo With Adaptive Layout
22 minutes ago
Simplicity and Siri AI Are HomeView's Killer Features, Apple Says
Simplicity and Siri AI Are HomeView's Killer Features, Apple Says
46 minutes ago
iPhone Duo Reviewers Really Miss Face ID
iPhone Duo Reviewers Really Miss Face ID
6 hours ago
Does the iPhone Duo Run Hot? Here's What Reviews Found
Does the iPhone Duo Run Hot? Here's What Reviews Found
7 hours ago
Apple Music's New Look is Now Live on Apple's Website
Apple Music's New Look is Now Live on Apple's Website
8 hours ago
Anthropic Launches Claude Duet, a Proactive AI Agent
Anthropic Launches Claude Duet, a Proactive AI Agent
8 hours ago
What 32,000 Folds Did to the iPhone Duo's Hinge
What 32,000 Folds Did to the iPhone Duo's Hinge
9 hours ago
iPhone Duo's Hidden FaceTime Camera Takes 'Trash' Photos
iPhone Duo's Hidden FaceTime Camera Takes 'Trash' Photos
11 hours ago
iPhone Duo Has 'Edge Light' Feature That Debuted on Macs Last Year
iPhone Duo Has 'Edge Light' Feature That Debuted on Macs Last Year
11 hours ago
Apple Support App Updated for iPhone Duo's Larger Display
Apple Support App Updated for iPhone Duo's Larger Display
11 hours ago
Amazon Sweetens the Deal on Entry-Level 16-Inch MacBook Pro With $570 Off
Amazon Sweetens the Deal on Entry-Level 16-Inch MacBook Pro With $570 Off
12 hours ago
iPhone Duo Tips Over on MagSafe Stands When Unfolded
iPhone Duo Tips Over on MagSafe Stands When Unfolded
12 hours ago
Apple Music's New Look Officially Announced
Apple Music's New Look Officially Announced
13 hours ago
iPhone Duo Supports Apple Pencil Starting With iOS 27.2
iPhone Duo Supports Apple Pencil Starting With iOS 27.2
14 hours ago
iPhone Duo Accessories Roundup: Cases and Screen Protectors From OtterBox, ZAGG, and More
iPhone Duo Accessories Roundup: Cases and Screen Protectors From OtterBox, ZAGG, and More
15 hours ago
Apple Stores Will Have 'Limited' Availability of iPhone Duo for Walk-In Customers
Apple Stores Will Have 'Limited' Availability of iPhone Duo for Walk-In Customers
15 hours ago
iPhone Duo Reviews Explain Why Device is Both 'Fun' and 'Frustrating'
iPhone Duo Reviews Explain Why Device is Both 'Fun' and 'Frustrating'
15 hours ago
Apple Says 'Reachability' Feature Coming to iPhone Duo Later This Year
Apple Says 'Reachability' Feature Coming to iPhone Duo Later This Year
17 hours ago
Loop Capital Cuts Apple Rating Over iPhone Sales Outlook
Loop Capital Cuts Apple Rating Over iPhone Sales Outlook
21 hours ago
Apple Stores in Bordeaux and Lille Looted During French Protests
Apple Stores in Bordeaux and Lille Looted During French Protests
21 hours ago
Bluesound Adds Native Apple Music Support
Bluesound Adds Native Apple Music Support
21 hours ago
Apple CEO John Ternus Explains What Makes Good Product Design
Apple CEO John Ternus Explains What Makes Good Product Design
22 hours ago
UK Proposes New Ways to Help Apple Pay Rivals
UK Proposes New Ways to Help Apple Pay Rivals
1 day ago
WhatsApp Developing In-App Browser for All Chat Links on iPhone
WhatsApp Developing In-App Browser for All Chat Links on iPhone
1 day ago
Apple's App Store Chief Explains Its Push for Premium Games
Apple's App Store Chief Explains Its Push for Premium Games
1 day ago
Apple Could Owe Even More After $5.7 Billion Patent Verdict
Apple Could Owe Even More After $5.7 Billion Patent Verdict
1 day ago
Skyrim Comes to Apple Silicon Macs With New Unofficial Installer
Skyrim Comes to Apple Silicon Macs With New Unofficial Installer
1 day ago
Apple Highlights Mac and iPad Use in Paris Design Exhibition
Apple Highlights Mac and iPad Use in Paris Design Exhibition
1 day ago
Apple Seeks 6G Modem Engineers as It Plans for Post-5G iPhones
Apple Seeks 6G Modem Engineers as It Plans for Post-5G iPhones
1 day ago
First iPhone Duo Unboxing Video Appears Ahead of Friday Launch
First iPhone Duo Unboxing Video Appears Ahead of Friday Launch
1 day ago