How to Block Scam Calls Automatically on iPhone & Android

Quick Answer: Block unknown calls automatically by enabling “Silence Unknown Callers” on iPhone (Settings > Phone) or “Filter spam calls” on Android (Phone app > Settings > Caller ID & spam). Both send all unknown calls to voicemail without ringing.

If you have a number you want to check before deciding whether to call back, try Scamwise — free, instant, no account needed.

Why Automatic Blocking Matters

Manually blocking numbers doesn’t work against scammers—they use new numbers constantly. Automatic filtering catches patterns and flags suspicious calls before they ring, saving you from spammy interruptions and scammy encounters.

iPhone: Block Unknown Calls Automatically

Option 1: Silence Unknown Callers

This sends all calls from numbers not in your contacts to voicemail silently.

To enable on your iPhone:

1. Open Settings
2. Tap Phone
3. Scroll to Silence Unknown Callers
4. Toggle On

Note: Calls from numbers you’ve recently called or texted will still ring, even if they are technically not in your contacts.

Option 2: Carrier Screening (Shows Labels)

If you want to see “Spam” or “Scam Likely” labels but still have calls ring:

1. Open Settings
2. Tap Phone
3. Tap Call Blocking & Identification
4. Enable any available carrier options

This varies by carrier. AT&T, Verizon, and T-Mobile all have options here.

Android: Block Scam Calls Automatically

Google Phone App (Pixel, many Android phones)

1. Open the Phone app
2. Tap the three-dot menu > Settings
3. Tap Caller ID & spam
4. Enable See caller and spam ID
5. Enable Filter spam calls to send spam to voicemail automatically

Samsung Phones

1. Open the Phone app
2. Tap More (three dots) > Settings
3. Tap Caller ID and spam protection
4. Toggle on Caller ID and spam protection
5. Toggle on Block spam and scam calls for automatic blocking

Where These Features Fall Short

Spoofing Known Contacts

Caller ID cannot be fully trusted. In family emergency scams, for example, callers may spoof a known contact number and this will not be detected by any of the controls above. Learn more about how Caller ID spoofing works.

Important Unknown Callers

At Savi, we think not just about how to block malicious calls, but also how to surface the unknown but important calls — your kid’s school, a delivery app, a ride-share service. As voicemail gets crowded with silenced calls, it’s easy to lose track of these too.

Tips for Best Results

• Layer protections: Use phone settings + carrier service + a scam protection app like Savi
• Check voicemail: Legitimate callers leave messages
• Save important numbers: Add doctors, schools, etc. to contacts
• Report spam: Helps improve databases for everyone

FAQs

Will I miss important calls if I block scam calls on my device?

Unknown calls go to voicemail, not blocked entirely. Check voicemail regularly.

What if a legitimate caller gets blocked?

They can leave voicemail. Add their number to contacts for future calls.

Do I need paid apps?

Free phone settings and carrier services work well for most people. Paid apps offer extra features like real-time scam detection and call summaries.

Does this stop all scam calls?

It significantly reduces them. No solution is 100% effective — that’s why layering multiple protections matters.