The short answer
Your iPhone can stop unknown calls from ringing in about a minute. Unknown means any number that is not saved in your Contacts.
Calls from numbers you haven’t saved now go straight to voicemail without ringing, and they still show in your list of calls. If you would rather know who it is first, choose Ask Reason for Calling instead. Either way, save the numbers you can’t afford to miss before you start.
How to silence unknown callers on iPhone
On iOS 26 and iOS 27 there is no separate switch called Silence Unknown Callers any more. It became one of three choices under Screen Unknown Callers, in Settings, Apps, Phone:
| Choice | A call from a number you haven’t saved |
|---|---|
| Never | Rings as usual. |
| Ask Reason for Calling | The iPhone answers quietly and asks for the caller’s name and reason. It rings only after they reply, and shows you what they said. |
| Silence | Does not ring. It goes to voicemail and appears in your list of calls. |
People saved in your Contacts ring as usual whichever you choose. FaceTime calls have a switch of their own: Settings, Apps, FaceTime, Silence Unknown Callers.
On an older iPhone
If you don’t see Screen Unknown Callers, the iPhone is running iOS 18 or earlier. You can check in Settings, General, About, next to iOS Version. On those versions the old switch is still there:
- iOS 18: Settings, Apps, Phone, then turn on Silence Unknown Callers.
- iOS 17 and earlier: Settings, Phone, then turn on Silence Unknown Callers.
On these versions, Apple still lets three kinds of callers ring: your contacts, numbers you called recently, and numbers suggested by Siri.
To get Screen Unknown Callers, update in Settings, General, Software Update. iOS 27 runs on the iPhone 11 and newer and on the iPhone SE (2nd generation) and newer. The iPhone XR, XS and older stay on iOS 18 and keep the old switch. If an up-to-date iPhone still doesn’t show it, check Settings, General, Language & Region: screening works only in the languages Apple supports, English and Spanish among them in the US.
Silence or screen: which to choose
- Silence suits someone who checks voicemail every day and rarely hears from new numbers. It is the quietest choice: nothing unknown rings.
- Ask Reason for Calling suits most people. Robocalls rarely answer the question, and real callers still get through. But your phone still rings for you to decide, and anyone with a good story gets to tell it on your screen. Our guide to the iPhone’s call screener shows how it works and where it falls short.
- Never is for a day when you expect a call from a new number, such as a repair or a hospital. Switch back afterwards.
The real calls silencing can cost you
Silence can’t tell a scammer from a stranger you need. Every number you haven’t saved goes to voicemail, including:
- A new doctor’s office, a hospital or the pharmacy
- A delivery driver, or the ride you booked
- A school, a plumber or a contractor
- Family calling from a hospital phone, a work line or a borrowed phone
Many of these callers hang up rather than leave a voicemail. So a silenced iPhone can be quiet and still miss the one call that mattered.
How to keep the calls you want
- Save the numbers you expect as contacts: doctors, the pharmacy, school, family members’ work numbers, the number on the back of your bank card. Saved numbers always ring.
- Check voicemail every day. In the Phone app it is under Calls, or under Voicemail if your Phone app uses the Classic layout.
- Save a real caller right away. When a silenced call turns out to be someone you need, add the number to your contacts so it rings next time.
- Expecting a new number? Set Screen Unknown Callers to Never for the day, then set it back.
Apple adds two exceptions of its own. If you call emergency services, screening turns off for 24 hours so a callback can reach you. And calls are not screened while you are roaming, whatever the setting.
Hide unknown callers from your call list
A separate setting tidies your list of calls without changing what rings:
- Open Settings, tap Apps, then Phone.
- Scroll down to Call Filtering.
- Turn on Unknown Callers. Missed calls and voicemails from unknown numbers move to a list of their own.
- Turn on Spam as well. Calls your carrier identifies as spam or fraud are silenced, sent to voicemail and moved to a Spam list.
To look through those lists, open the Phone app, go to Calls (or Recents in the Classic layout), tap the Filter button and choose Unknown Callers or Spam. If a number there is someone you know, tap Mark as Known next to the call. Its future calls then stay out of the Unknown Callers list.
Stopping unknown calls on a parent’s iPhone
If you are doing this for a parent, both of Apple’s choices leave a gap:
- Silence sends the new specialist and the pharmacy to a voicemail box your parent may never check.
- Ask Reason for Calling still rings your parent and leaves them to judge a stranger’s story. A scammer always has one ready.
- Neither helps their landline, and neither tells you what happened.
PhoneShield answers those calls for them. Their number is forwarded once, on their phone, to a PhoneShield number, and every call meets PhoneShield first:
- Known scam numbers are refused before the phone rings: calls the network labels Scam Likely or Spam Risk, numbers on our shared scam list, and numbers with repeated FTC complaints.
- Family and the other contacts you add ring straight through in the PhoneShield app, with their name on the screen.
- Everyone else is asked who they are and why they are calling. A real reason rings through. Sales pitches and scam scripts are declined. Anyone else can leave a message.
- You can look after it from your own account: add the people who should always get through, and see every call and message.
Set it up together, with your parent’s agreement. It takes about ten minutes. PhoneShield is $29.99 a month or $299 a year for one line, and it reduces scam calls a great deal without promising to stop every one. See how it works and the plan.
Questions people ask
How do I stop unknown calls on my iPhone?
Open Settings, tap Apps, then Phone, and scroll down to Screen Unknown Callers. Choose Silence to send every number that is not in your contacts straight to voicemail, or Ask Reason for Calling to have the iPhone ask who is calling before it rings. Save the numbers you can't afford to miss as contacts first.
Where is Silence Unknown Callers on iPhone?
Since iOS 26 it is no longer a switch of its own. It is the Silence choice under Screen Unknown Callers, in Settings, Apps, Phone. On iOS 18 the Silence Unknown Callers switch is in Settings, Apps, Phone, and on iOS 17 and earlier in Settings, Phone.
Does silencing unknown callers block them?
No. A silenced call doesn't ring, but it still goes to your voicemail and shows in your list of calls, so the caller can leave a message. To stop one number for good, block it instead.
Will I miss important calls if I silence unknown callers?
You may. Every number that is not in your contacts goes to voicemail without ringing: a new doctor's office, the pharmacy, a delivery driver, a hospital calling about a relative. Many of them hang up rather than leave a message. Save the numbers you expect, check voicemail every day, or choose Ask Reason for Calling instead.
Does Silence also stop No Caller ID calls?
Yes. A hidden number can't match anyone in your contacts, so the iPhone treats it as unknown: Silence sends it to voicemail, and Ask Reason for Calling screens it.
Can I silence unknown callers on my parent's iPhone from my own phone?
No. The setting lives on their iPhone, so it has to be changed there. With PhoneShield, call forwarding is turned on once on your parent's phone, together. After that the family manages favorites and sees calls and messages from their own account.
Sources
- Apple Support, Manage unknown callers on iPhone: the three choices, Call Filtering, roaming and emergency calls
- iPhone User Guide for iOS 27, Screen and block calls: what Silence does, the Unknown Callers list, Mark as Known
- iPhone User Guide for iOS 18, Block or avoid unwanted calls: the old Silence Unknown Callers switch
- iPhone models compatible with iOS 27
Checked October 18, 2026, on iOS 27.