Caller ID spoofing: why the number that called you may be fake

Who Called Australia editorial team · Updated: 31/08/2026

The number on your screen is whatever the calling system chose to send. That's not a bug in your phone — it's how caller ID has always worked. Legitimate systems use it so the callback number makes sense; scammers use it to look like your bank, a government agency or your next-door neighbour. Understanding this one fact rewires how you treat every unknown call.

How the trick works

On modern VoIP infrastructure, the calling party sets the outbound display number in software. International scam operations route calls through chains of providers, and by the time the call reaches an Australian network the display says whatever was configured: a real bank's 13 number, an 02 landlinein your city, or a mobile one digit different from yours ("neighbour spoofing" — local-looking calls get answered). The person who legitimately holds that number knows nothing about it.

What changed with the Reducing Scam Calls code

Since the ACMA registered the industry's Reducing Scam Calls codein December 2020, Australian carriers must identify, trace and block scam call traffic, and share intelligence with each other. The result is real — billions of calls have been blocked at network level — and visible in the wild: mass waves of "Chinese embassy" robocalls and crude ATO threats dropped sharply. What remains is the more targeted traffic: bank impersonation with a cleanly spoofed institutional number, and scripts that rotate numbers faster than blocklists update.

Both directions of the harm

You receive a spoofed call:the display proves nothing, so verification must happen out-of-band — hang up and dial the organisation's published number yourself. The 60-second check covers the rest.
Your number gets spoofed:suddenly strangers call you back angrily, or accuse you of scam calls you never made. You're a victim, not a suspect: the calls didn't transit your phone or your account. Report it to your carrier and Scamwatch, warn callers-back, and wait it out — spoofing waves move on quickly because recycled displays stop being useful.

What this means for number lookups

It means a lookup tells you about the number, never conclusively about the caller. When a number's page here fills with identical scam reports, the overwhelmingly likely story is a scam operation using that display — sometimes at the expense of an innocent holder. That's why our pages label community content as the reporters' opinion, why register data (methodology) is quoted as "range allocated to…" rather than "this caller is…", and why affected number holders can dispute content via data removal.

Frequently asked questions

People say my number is calling them, but I never called. What do I do?

Your number is being spoofed as a display. You don't need to change it: spoofing runs happen in waves and typically move on within weeks. Tell callers-back that your number was faked, don't engage with angry return calls, and report the wave to your carrier and Scamwatch. A note on your number's page here helps too.

Is spoofing illegal in Australia?

Using a fake caller ID to defraud is illegal, and carriers must combat it under the ACMA's Reducing Scam Calls code. But the technology itself has legitimate uses — a company showing its main 1300 number from every desk, a doctor calling from a private line showing the clinic switchboard — so the display standard can't simply be abolished.

Can I tell from my phone whether a call is spoofed?

Not reliably. A genuine-looking Australian number can be fake, and calls the network itself flags get blocked before reaching you. Practical rule: treat the display as a hint about legitimate calls and as noise on suspicious ones. Verification happens by calling back on the published number, never by trusting the screen.

Why can't telcos just block all spoofed calls?

They block a lot — Australian carriers have stopped billions of scam calls since the Reducing Scam Calls code took effect in late 2020 — but international VoIP traffic hops through many networks, and each hop can rewrite the display. Blocking everything unverified would also kill legitimate traffic, so filtering keeps improving without ever reaching zero.