How to protect yourself from spam calls

Spam calls are a nuisance and, at their worst, a financial threat. Americans receive billions of robocalls a year; Canadians face the same problem at a smaller scale. There's no single fix, but a handful of settings and habits together will reduce the flood by 90% or more.

iPhone: two settings that do most of the work

• Silence Unknown Callers. Settings → Phone → Silence Unknown Callers. Any number not in your contacts, recent outgoing calls, or Siri suggestions is sent silently to voicemail. Legitimate callers leave a message; spammers don't.
• Focus modes. Set a Focus that only allows contacts through during work or sleep hours.

Android: use the built-in caller ID and spam filter

In the Google Phone app: Settings → Caller ID & spam. Turn on both "See caller and spam ID" and "Filter spam calls." Google uses its massive database of reported numbers to label or auto-reject known spam before your phone rings.

Register on the national do-not-call list

• United States: Register free at donotcall.gov. Legitimate telemarketers are legally required to check this list within 31 days.
• Canada: Register free at the CRTC's National Do Not Call List at lnnte-dncl.gc.ca.

These lists don't stop overseas scammers, but they cut domestic telemarketing sharply.

STIR/SHAKEN and carrier-level blocking

US and Canadian carriers are now required to implement STIR/SHAKEN — a caller ID authentication framework that tags calls as verified, unverified, or spoofed. AT&T, Verizon, T-Mobile, Rogers, Bell, and Telus all offer free spam-blocking apps or built-in filtering that use this data. Check your carrier's account settings and turn on their spam filter if it isn't already on.

Verify before you call back

If a number left a voicemail claiming to be your bank, courier, or a government office, look up the number before calling back. A phone lookup will tell you the state or province, carrier, and line type. If a "Chase Bank" is calling from a VoIP number with no carrier of record, you've saved yourself trouble.

Habits that help

• Don't say "yes" to opening questions. Scammers record audio of you saying "yes" to reuse in fraud claims.
• Never share OTPs, passwords, SSN, or SIN over the phone. No legitimate bank or agency asks for them by phone.
• Hang up and call the institution back on their published number — not the number that called you.
• Don't call back missed international numbers you don't recognize. Some are premium-rate traps that charge per minute connected.

Third-party apps (use with judgment)

Apps like Truecaller, Hiya, and Nomorobo identify spam by crowdsourced reports. They work — but the trade-off is your entire contact list gets uploaded to their servers. For many people that trade is worth it; for privacy-conscious users, the built-in Apple and Google filters plus your carrier's own spam blocker are usually enough.