If you don't have business or family abroad, the simplest way to eliminate ~80% of phone scams is to block international calls entirely. Here's how to do it on every platform.
On iPhone
iOS doesn't have a native "block all international" toggle, but you can get close:
- Settings → Phone → Silence Unknown Callers. Enable this. Any call from a number not in your contacts goes straight to voicemail. This is the single most effective setting on iOS.
- Settings → Focus → Do Not Disturb → People. Allow only contacts. Combine with Silence Unknown Callers for double protection.
- For specific countries: open the Phone app → Recents → tap (i) next to the number → Block this Caller. You'll need to do this per number.
On Android (Google Phone app)
- Open Phone app → tap menu (three dots) → Settings → Spam and Call Screen.
- Enable See caller and spam ID.
- Enable Filter spam calls. Suspected spam goes straight to voicemail.
- For Pixel phones: enable Call Screen to have Google Assistant answer unknown calls.
Carrier-level blocking (US)
The most effective protection is at the carrier level, before the call even reaches your phone.
AT&T
- Free: AT&T ActiveArmor app (formerly Call Protect). Download from App Store / Play Store, sign in with your AT&T account, enable Spam Risk blocking.
- Free in-app: enable "Block Spam Risk Calls" automatically.
Verizon
- Free: Verizon Call Filter app, included with your plan.
- Settings → Block Calls → Enable High level filter. This blocks high-risk spam automatically.
- Premium ($3.99/mo) adds caller ID for unknown numbers.
T-Mobile
- Scam Shield is free and on by default.
- Dial
#662#to enable Scam Block (blocks calls T-Mobile is highly confident are scams). - Download the Scam Shield app for finer control.
Carrier-level blocking (UK)
- EE / Vodafone / O2 / Three: all support call blocking via carrier apps. EE has free Spam Shield. Vodafone offers Call Protect. Most UK carriers also support TPS (Telephone Preference Service) registration at tpsonline.org.uk.
Third-party apps
If your carrier's tools aren't enough:
- Truecaller (free + premium) — community-sourced spam database, very effective for international scam numbers.
- Hiya — partnered with AT&T and Samsung. Strong spam detection.
- Robokiller ($4/mo) — uses "answer bots" to waste scammers' time.
When blocking isn't enough: silence everything
If you're getting hammered with scam calls and nothing helps, the nuclear option is:
- Enable Silence Unknown Callers (iOS) or Block all unknown callers (Android).
- Enable carrier spam blocking at the strictest level.
- Add legitimate businesses and doctors to your contacts so they can still reach you.
Yes, you'll miss the occasional legitimate call. But spam will drop by 95%+, and real callers can leave voicemail or text.
What about RCS / iMessage scams?
Blocking calls doesn't block SMS scams. For text scams, on iPhone go to Settings → Messages → Filter Unknown Senders. On Android, use Google Messages' built-in spam protection.
Bottom line
The single most effective action: enable Silence Unknown Callers (iPhone) or your carrier's automatic spam blocking. Real callers will leave voicemail. Scammers won't bother. You'll save hours of frustration and probably your bank account.