Your phone rings once and stops. The number is international, often from a country code you do not recognise. Curiosity or the worry that it was important prompts a return call. That call connects to a premium rate service, and the charge accrues for as long as you stay on the line.

Why you are kept waiting

The answering system is designed to hold you: hold music, a recorded message claiming the call is being connected, or a voice asking you to wait. Every second is billed at a premium rate shared between the fraudster and intermediary carriers. The scheme is called Wangiri, and it operates at scale through automated dialling.

  • A message claiming a missed delivery or voicemail, asking you to call a premium number to arrange it.
  • Subscription traps where replying to an SMS enrols you in a recurring premium service.
  • Fraudulent "support" numbers placed in search advertising for banks, airlines and government services.

What to do

Do not return calls from unfamiliar international numbers. Anyone with a genuine reason to reach you will call again or leave a message. Check your bill after any suspicious activity; operators will often credit premium charges arising from recognised fraud, and they track the numbers involved. Block the number and report it to your operator and to the telecom regulator, which can order blocking at network level.