Step-by-step guide to blocking spam and robocalls on any iPhone using built-in features, Silence Unknown Callers, and third-party apps.
Go to Settings > Phone > Silence Unknown Callers. When enabled, calls from numbers not in your Contacts, Mail, or Messages are sent directly to voicemail without ringing. The call still appears in your Recents list, and callers can leave a voicemail.
This feature uses Siri intelligence to allow calls from numbers you've recently communicated with, even if they're not saved contacts. It's the single most effective built-in tool against robocalls, but be aware it will also silence legitimate calls from new contacts — doctors' offices, delivery drivers, etc.
To block a specific number: open the Phone app > Recents, tap the (i) icon next to the number, scroll down, and tap "Block this Caller." Blocked callers go straight to voicemail and can't send you texts or FaceTime calls.
You can manage your blocked list at Settings > Phone > Blocked Contacts. While useful for known harassment numbers, blocking individual numbers is largely ineffective against robocallers who use different numbers for every call.
When you receive a call that iOS identifies as potential spam, a "Junk" label appears below the number. After hanging up, you can report the number by tapping "Report Junk" in your recent calls. This data feeds back to Apple's spam detection database.
For text message spam, open the message, scroll to the bottom, and tap "Report Junk." Apple forwards reported messages to the carrier and uses the data to improve future spam detection. Enable Settings > Messages > Filter Unknown Senders to automatically sort texts from non-contacts into a separate tab.
Nomorobo ($1.99/month) — maintains a constantly-updated database of known robocall numbers and blocks them before they ring. Effective against the highest-volume offenders. Hiya (free basic, $3.99/month premium) — provides real-time caller ID for unknown numbers, showing the likely caller name and spam risk score. RoboKiller ($4.99/month) — goes beyond blocking by using AI to answer scam calls with realistic-sounding bots that waste scammers' time.
All three apps integrate with iOS Call Kit to provide seamless call screening. Performance varies by region, so consider trying free tiers or trial periods before committing. The combination of iOS's built-in Silence Unknown Callers + one third-party app provides strong protection.
AT&T ActiveArmor (free basic tier): automatically blocks likely-fraud calls and labels suspected spam. T-Mobile Scam Shield (free): identifies and blocks scam calls network-wide, with a premium tier ($4/month) that adds caller ID for unknown numbers. Verizon Call Filter (free basic): screens incoming calls and alerts you to spam risk.
Carrier-level blocking happens at the network before calls reach your phone, making it more efficient than app-based blocking. Most carriers offer a free tier that provides meaningful protection — activate it through your carrier's app or by calling customer service.
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