A call displayed as No Caller ID does not provide a normal phone number that you can add to the iPhone’s blocked-contacts list. Instead, use the iPhone’s call-screening and unknown-caller controls to reduce interruptions from callers who are not recognized.
Review Unknown-Caller Screening
- Open Settings.
- Tap Apps.
- Tap Phone.
- Find the call-screening or unknown-caller controls available on your version of iOS.
- Choose the behavior that fits your needs.
Current iOS versions can provide options for handling calls from unsaved numbers, including screening or silencing behavior depending on your software and configuration.
Block a Caller When a Number Is Available
- Open Phone.
- Tap Recents.
- Tap the information button beside the caller.
- Choose Block Caller.
Why No Caller ID Is Different
If the caller has deliberately withheld identifying information, there may be no unique number for the iPhone to place on its normal block list. Screening unknown callers is therefore more useful than repeatedly searching for a nonexistent No Caller ID contact.
Be Careful With Legitimate Calls
Doctors, schools, delivery services, businesses, and other legitimate callers can use numbers that are not saved in Contacts. Aggressive screening can therefore hide calls you actually want. Check voicemail and recent calls when you are expecting an important contact.
Persistent Harassment
If calls are threatening or harassing, preserve useful records and contact your carrier or appropriate local authorities rather than relying only on an iPhone setting.
Use Live Voicemail as Another Filter
If you do not want to silence every unfamiliar number, allowing an unknown call to go to voicemail can provide context before you answer or call back. Never return a suspicious call merely because the caller leaves an urgent message; verify the organization through a trusted number first.