How to Stop Spam Calls on iPhone and Android

Your phone rings. It’s a local-looking number, so you answer. Silence, then a recording about your car’s extended warranty. Again.

Spam calls are more than a nuisance. Many are scams that impersonate banks, government agencies, delivery companies or even family members. There’s no single switch that stops them all, but stacking 3 or 4 layers of protection gets most people from several junk calls a day down to almost none. Here’s how each layer works and how to set it up.

Why you get so many spam calls

Robocallers use autodialers that can place huge numbers of calls cheaply, and they often fake (spoof) the caller ID to look like a local number or a trusted business. Your number may be on lists bought, sold or leaked over the years.

The phone industry has been fighting back. The FCC required the largest voice providers to implement STIR/SHAKEN caller ID authentication in their IP networks by June 30, 2021, under the TRACED Act. That technology helps carriers check whether a call really comes from the number shown, which powers the “Spam Likely” or “Scam Likely” labels you may see. In February 2024, the FCC also ruled that AI-generated voices count as “artificial” voices under the Telephone Consumer Protection Act, making voice-cloned robocalls illegal without prior consent, apart from limited exceptions.

These rules help, but scammers operating overseas often ignore them. That’s why the settings on your own phone matter.

Layer 1: built-in call screening on your phone

iPhone: Screen Unknown Callers

On recent versions of iOS, go to Settings, Apps, Phone and find Screen Unknown Callers. Apple offers 3 options:

• Never: Unknown numbers ring normally.
• Ask Reason for Calling: The caller is asked to state their name and reason before your phone rings, and you see their answer.
• Silence: Unsaved numbers go straight to voicemail and appear in Recents.

Apple notes that calls aren’t screened while you’re roaming, and screening turns off for 24 hours after you call emergency services. You can also block a specific number by tapping the info button next to a call in Recents and choosing Block Caller. Menu paths differ slightly between iOS versions, so search Settings for “unknown callers” if you don’t see it.

Android: spam filtering and Call Screen

On phones that use the Google Phone app, including Pixel phones, open the Phone app, Settings, Caller ID and spam, and turn on spam filtering so suspected spam calls don’t ring. Pixel phones also offer Call Screen, where your phone answers unknown callers on your behalf, asks who’s calling and shows you a live transcript.

Samsung phones include their own caller ID and spam protection in the Phone app settings. Other manufacturers vary, so look for “spam,” “block” or “caller ID” in your Phone app settings.

Layer 2: your carrier’s free spam tools

All 3 major US carriers offer free spam and scam call protection, usually with paid upgrades. Examples include AT&T ActiveArmor, T-Mobile Scam Shield and Verizon Call Filter. Smaller carriers and prepaid brands often offer similar tools. Features, names and pricing change, so check your carrier’s app or website.

Typical free features include:

• Labeling suspected spam calls
• Automatically blocking calls flagged as high-risk fraud
• A personal block list

Comparing your options

Key takeaway: No single tool catches everything. Combine phone screening with carrier filtering, and save legitimate contacts so the calls you want always ring through.

Layer 3: the National Do Not Call Registry

The FTC’s National Do Not Call Registry is free. Register at DoNotCall.gov or call 1-888-382-1222 from the phone you want to add. According to the FTC:

• Your registration doesn’t expire. Numbers are only removed if they’re disconnected and reassigned, or if you ask.
• Your number usually appears on the registry the next day, but telemarketers have up to 31 days to stop calling.
• Political, charitable, debt collection, informational and survey calls are still allowed, as are calls from companies you’ve recently done business with.
• Robocalls trying to sell you something are illegal without your written permission, whether or not you’re registered.

The registry is effective against legitimate telemarketers. Scammers don’t follow the law, so if you’re on the list and still getting sales robocalls, they’re very likely scams.

Layer 4: habits that keep you off more lists

Your behavior matters as much as your settings:

• Don’t answer unknown numbers if you can avoid it. Let voicemail handle them.
• Never press a number to “be removed from the list.” The FTC advises hanging up instead, since pressing buttons can confirm your number is active.
• Don’t call back missed calls from unknown numbers, especially international ones.
• Never give personal information or payment to an incoming caller. Hang up and call the organization at a number from its official website or your statement.
• Watch for voice cloning. Scammers can mimic a relative’s voice. Agree on a family code word and verify by calling back. Our guide on how to spot a deepfake explains the warning signs.
• Be careful where you share your number. Check the privacy settings on shopping, social and contest sites. Our US state data privacy laws guide explains the rights some states give you over your data.

Stopping spam texts too

Spam texts work the same way. On iPhone, turn on Filter Unknown Senders in Messages settings. On Android, Google Messages includes spam protection in its settings. You can forward spam texts to 7726 (SPAM) to report them to most US carriers, and then delete them. Never tap links in unexpected texts about packages, tolls or account problems.

How to report spam and scam calls

Reporting helps regulators and carriers track down bad actors:

1. Unwanted sales calls with no money lost: report at DoNotCall.gov.
2. Scams or money lost: report at ReportFraud.ftc.gov.
3. Caller ID spoofing or robocall complaints: file with the FCC’s consumer complaint center.
4. Through your carrier: many carrier apps let you report a number directly.

If you lost money, also contact your bank or card issuer right away.

Where to start: a 15-minute setup

1. Turn on Screen Unknown Callers (iPhone) or spam filtering and Call Screen (Android).
2. Open your carrier’s app and activate its free spam protection.
3. Register your number at DoNotCall.gov.
4. Save the numbers of your doctors, pharmacy, kids’ school and other important contacts, so screening doesn’t block them.
5. Turn on text filtering in your messaging app.
6. Share these steps with older relatives. Our guide on setting up a phone for a senior includes scam protection as part of a full setup.

If you run a small business and spam calls are tying up your line, the same principles apply to business phone systems, many of which include spam filtering. Browse our top lists for local tech providers that can help.

Conclusion

You can’t stop every spam call, but you can make them rare. Turn on your phone’s screening, activate your carrier’s free tools, register with the Do Not Call Registry and build a few simple habits. Most important, treat any unexpected call asking for money or personal details as a scam until you’ve verified it yourself.

Sources

• FTC: National Do Not Call Registry FAQs — how to register, 31-day window, exempt calls and reporting
• FCC: Combating Spoofed Robocalls with Caller ID Authentication — STIR/SHAKEN mandate and June 30, 2021 deadline
• FCC: FCC Makes AI-Generated Voices in Robocalls Illegal — February 2024 TCPA declaratory ruling
• Apple Support: Manage unknown callers on iPhone — Screen Unknown Callers options and limits
• Apple Support: Screen and block calls on iPhone — blocking numbers and filtering spam calls