Low riskPhone & Voice Scams

Number Harvesting Robocall Scam

In this scam, robocalls with silence, a simple question, or a generic recording aim to confirm your number is active and reachable, marking it for more scam calls or recording responses for misuse.

Quick verdict

Risk level
Low risk
Scam type
Number validation (robocall)
Main red flag
A robocall with silence or a yes-or-no question like 'Can you hear me?'
What to do first
Do not respond; hang up rather than saying 'yes' or pressing keys.

What this scam usually looks like

In this scam, robocalls with silence, a simple question, or a generic recording aim to confirm your number is active and reachable, marking it for more scam calls or recording responses for misuse.

Example message pattern

Example pattern — not a real report
Example pattern: A call opens with silence or asks 'Can you hear me?' to get a 'yes' and confirm your number is live.

This is a fictional, anonymised example used to illustrate the pattern. It is not a verified real message, and any names are used only to show how the scam typically reads.

Red flags to watch for

  • Silence or dead air when you answer
  • A simple yes-or-no question to prompt a response
  • A generic recording with no real purpose
  • Calls that hang up once you answer
  • An uptick in scam calls afterwards

What to do

  • Hang up rather than responding or pressing keys
  • Do not say 'yes' or confirm details to robocalls
  • Use call-blocking and your carrier's spam tools
  • Report persistent robocalls

If you already clicked or replied

  • If you engaged, simply be alert for more scam calls
  • Do not act on any follow-up that cites your 'response'
  • Block numbers and tighten call filtering
  • Report it to your carrier

What not to do

  • Do not say 'yes' or answer prompts
  • Do not press keys to be removed
  • Do not engage with silent or generic robocalls

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Frequently asked questions

Why do robocalls stay silent or ask 'can you hear me?'
They confirm your number is active and reachable, marking it for more scam calls, and may record your voice. Hang up rather than responding.
Is saying 'yes' dangerous?
The bigger risk is confirming your number is live, leading to more calls. Avoid responding, and never authorise anything based on a recorded 'yes'.
How do I cut down these calls?
Use call-blocking and your carrier's spam tools, do not engage, and register with any call-preference service available.
Should I press a key to opt out?
No. Pressing keys confirms your number is active and usually leads to more calls. Just hang up.

Last reviewed: June 2026

Disclaimer: This page provides educational information only to help you recognise common scam patterns. It is not legal, financial, cybersecurity, or law enforcement advice, and it does not confirm whether any specific message, company, or person is genuine or fraudulent. When in doubt, contact the official organisation directly and report concerns to your local authorities.