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Guides 3 min read

How to Stop Robocalls

Three layers, all free: your phone's built-in silencing, your carrier's blocking service, and the Do Not Call registry. What each one actually stops, and the rule that matters most.

Jean Gilles
Founder & Lead Analyst, ShopCellPlans
Published July 27, 2026
Updated July 31, 2026

No single setting stops robocalls, because they arrive through several channels. Stacking three free layers eliminates most of them, and one behavioural rule prevents the rest from getting worse.

Key takeaways
Stack three free layers: phone silencing, carrier blocking app, and donotcall.gov.
Silence Unknown Callers (iPhone) and spam filtering (Android) remove most of the volume immediately.
Never respond, never press a key — engagement marks your number as live and increases calls.
The Do Not Call registry stops legal telemarketers, not scammers.
Spoofed local numbers and overseas calls are what still get through.

Layer 1 — your phone

  • iPhone: Settings > Apps > Phone > Silence Unknown Callers. Anyone not in your contacts, recent outgoing calls, or Siri suggestions goes straight to voicemail.
  • iPhone also offers Live Voicemail, which transcribes as the caller speaks — so you can see whether a silenced call was legitimate.
  • Android: open the Phone app > three-dot menu > Settings > Caller ID & spam, and enable both spam filtering and See caller and spam ID.
  • Both platforms let you block individual numbers, which is worth doing but ineffective on its own — robocallers rotate numbers constantly.
The rule that matters most
Never speak, never press a key, never say yes. Any response — even a word — confirms a live human answered, which makes your number more valuable and increases the calls. Let unknown numbers go to voicemail.

Layer 2 — your carrier

  • Verizon Call Filter — free spam detection and blocking, with a paid tier adding caller ID and a personal block list.
  • AT&T ActiveArmor — free fraud blocking and spam alerts, with a paid tier for reverse lookup and custom controls.
  • T-Mobile Scam Shield — free scam blocking and caller ID, plus a proxy number on some plans.
  • MVNOs inherit the host network's underlying protections but usually not the branded app. Check what your carrier's app offers — most people never turn it on.

Layer 3 — the registry and reporting

Register at donotcall.gov. It's free, permanent, and stops legitimate telemarketers, who face penalties for calling registered numbers. It does nothing against outright scammers, who are already breaking the law — but it meaningfully reduces the legal volume, and reporting violations at the same site is what drives enforcement.

What still gets through, and why

  • Spoofed local numbers — scammers fake a number matching your area code, because people answer those. STIR/SHAKEN authentication has reduced this but hasn't ended it.
  • Calls from abroad, where US enforcement doesn't reach.
  • Legitimate-but-unwanted calls from businesses you've done business with; the registry doesn't cover existing relationships.
  • Anything you engaged with previously. One answered call can produce months of follow-up.
Switching carriers? Check what spam protection comes with it

Blocking quality varies between networks and their MVNOs. See what each plan includes.

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#Robocalls #Spam #How-to
Jean Gilles
About the author

Jean Gilles has researched personal finance, consumer technology, and wireless pricing for over a decade. He founded ShopCellPlans in 2019 and writes every review on the site.

Frequently asked questions

Does the Do Not Call registry actually work? +
For legitimate telemarketers, yes — they face penalties for calling registered numbers. It has no effect on scammers, who are already operating illegally.
Is my carrier's spam blocking free? +
The core service is free on Verizon Call Filter, AT&T ActiveArmor, and T-Mobile Scam Shield. Each sells a paid tier adding caller ID lookup and custom block lists.
Why do robocalls come from my own area code? +
Spoofing — the caller fakes a local number because people are far more likely to answer one. STIR/SHAKEN call authentication has cut this down but not eliminated it.
Should I answer and press 9 to be removed? +
No. Those prompts confirm a real person answered, which typically increases the calls. Don't interact at all.
Will changing my number stop robocalls? +
Temporarily. New numbers get harvested within months. The layered blocking approach is more durable than a new number.
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