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Scam breakdown

Robocalls and Prerecorded Spam: Why They Call

Short answer

Robocalls play a prerecorded message to thousands of numbers at once, so they cost almost nothing to send. Some are legal (appointment reminders, political, some charities); sales robocalls without your written permission are not. You can't stop every one, but you can avoid the moves that invite more, then block and report the rest.

See the habit that works

We don't run a lookup database and never ask for your number or personal details.

Defense, not lookup
This page is about deciding whether to answer and how to block and report, not tracing who called.
Official sources
Guidance follows the FTC and FCC; report illegal robocalls at DoNotCall.gov and the FCC.
Independent guide
CallerCheck is not affiliated with any carrier or phone maker; settings vary by device and region.

What a robocall actually is

Four traits explain why robocalls flood phones and why caller ID can't be trusted.

  • A recorded message

    A pre-set voice plays automatically instead of a live person dialing you.

  • Sent at scale

    Software dials thousands of numbers at once, so it costs the sender almost nothing.

  • Caller ID spoofed

    The FTC says caller ID is spoofable, so a familiar name or area code proves nothing.

  • Not all illegal

    Some are allowed, like purely informational or debt-collection calls; sales robocalls without your written permission are illegal.

Note: Caller ID spoofing and carrier spam labels are covered in more depth in the caller ID spoofing guide and the carrier spam blocking guide.

Will your reaction bring more calls or fewer?

The band shows how well each action avoids inviting more robocalls.

  • You let unknown numbers go to voicemail

    High

    What helps: Not answering avoids confirming that a person picks up, the signal robocallers look for.

    What gets in the way: You may miss a real call, so check voicemail before deleting.

  • You press a key to 'opt out' or reach an operator

    Low

    What helps: Nothing reliable: callers breaking the law don't honor 'remove me' options.

    What gets in the way: The FTC warns that pressing a key confirms a live number and usually leads to more robocalls.

  • You block the specific number that called

    Medium

    What helps: That exact number stops ringing your phone.

    What gets in the way: Scammers rotate numbers, so a new one can call the next day.

  • You turn on carrier labeling or silence-unknown-callers

    Medium

    What helps: Carrier spam labels (such as 'Scam Likely') and silencing cut how many spoofed calls reach you.

    What gets in the way: The FCC says authentication reduces illegal spoofing but does not eliminate it.

  • You report the call to DoNotCall.gov or the FCC

    Low

    What helps: Reports feed enforcement against the companies behind illegal robocalls.

    What gets in the way: It rarely stops your own calls quickly; treat it as a long game, not a fix.

Note: No setting blocks every robocall; senders rotate numbers and spoof caller ID. Options and results vary by carrier, phone, and OS version.

A phone speaker emitting an identical, repeating prerecorded waveform.
Illustration, not a real phone interface.

The one habit that works: don't engage, block, report

Four steps you can repeat on any robocall, on iPhone or Android.

Nothing to sign up for. Blocking menus differ by phone and carrier, so see the blocking guide for exact steps.

  1. Don't answer unknown numbers

    Let calls from numbers you don't recognize go to voicemail; a real caller can leave a message.

  2. Never press a key or speak

    If a recording asks you to press 1 or say a word to be removed, hang up instead.

  3. Block it and turn on filtering

    Block the number in your phone and switch on your device or carrier's spam filtering.

  4. Report an illegal robocall

    Report it at DoNotCall.gov or file a complaint with the FCC; report fraud at ReportFraud.ftc.gov.

Report a robocall at DoNotCall.gov →

Questions people ask

Should I press 1 to be taken off the list?

No. The FTC warns that pressing any key, even to 'opt out' or reach an operator, can lead to more robocalls, because it shows a real person answered. Press nothing and hang up.

Are all robocalls illegal?

No. Purely informational robocalls, such as appointment reminders, and some political and charity calls can be legal, though rules differ for cell phones. The FTC says a robocall trying to sell you something is illegal unless the company got your written permission first.

Why does the line go silent or hang up right after I answer?

Auto-dialers call more numbers than they have recordings or agents for, and some calls only check whether a person picks up. Silence or a click after you answer is a sign your number was just confirmed live. Hang up, don't call back, and block the number if it repeats.

I blocked the number but they called again from a new one. Why?

Robocall senders rotate through many numbers, so blocking one only stops that one. Combine blocking with your carrier's labeling or a silence-unknown-callers setting, and don't engage when they do get through.

Where do I report an illegal robocall?

Report illegal robocalls at DoNotCall.gov and file a complaint with the FCC at no cost. If it was a scam and you lost money or shared information, also report it at ReportFraud.ftc.gov.

Official sources

Rules and phone settings change. Check the current page before you act.