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Calling Line Identification (CLI) overstamping and spoofing

Calling Line Identification and what to do if your number is spoofed.

Calling Line Identification

If your phone has a display screen, Calling Line Identification (CLI) allows you to see the telephone number of the person calling before you answer your phone.

In July 2022, we registered Industry Code C661:2022 Reducing Scam Calls and SCAM SMs. It includes new rules to improve CLI accuracy and places obligations on carriers and carriage service providers to identify, trace and block SMS scams and scam calls.

CLI overstamping

CLI overstamping allows the person calling you to display a different number from the number they are calling from.

For example, an Australian company which operates an overseas call centre may overstamp their calls (which originate from overseas) with an Australian number so that you recognise this number and return a call.

This is legal in Australia unless it is being done for unlawful or malicious purposes, most commonly to carry out scams. This is often referred to as caller ID spoofing.

The Industry Guidance Note (IGN 009) CLI Management provides information on CLI overstamping and CLI spoofing. 

Freephone or local rate number (13, 1300 or 1800 numbers), and invalid or unallocated Australian numbers, cannot be used for CLI overstamping.

You may discuss CLI management and overstamping directly with your telco.

ID spoofing

Caller ID spoofing allows the scammer to deliberately hide their number, and display a different (often Australian) number, increasing the likelihood that you answer the call.

Typically, these callers are located overseas and may be impersonating a bank, a government agency or a telecommunications provider to get your personal or financially sensitive information for fraudulent purposes.

How you can protect yourself

Beware of suspicious calls and note that most trusted institutions, including banks, will never ask you to provide financial details over the phone. Never send money or gift cards, or give out your credit card or bank details.

Scammers may threaten you with a fine, telephone disconnection, legal costs, or sometimes suggest you will be arrested or deported.

If you receive a suspected scam call you should:

  • Hang up, then check if their story is real by calling the actual organisation
  • Never give out any personal or financial information
  • Contact your telco to seek assistance
  • Report the scam to ACCC’s Scamwatch
  • Report the scam to ReportCyber 
  • Contact IDCARE (call on 1800 595 160) if you’ve had personal details stolen
  • If bank fraud has been committed, report it to your bank or financial institution immediately and also to the police.

What to do if your number is spoofed

If you get calls from people saying your number is showing up as their caller ID, it's likely that your number has been maliciously spoofed.

If you believe your number has been spoofed by a scammer, you should contact your telco immediately.

Do not answer calls from unknown numbers and you can also place a message on your voicemail to alert callers that your number has been maliciously spoofed.

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