Accounts & passwords
What is SIM swap fraud, and how do I protect my phone number?
Your mobile number is more than a way to make calls. It receives the codes that protect your bank, email and social media. If a criminal moves your number to their SIM, those codes go to them. Australian telcos now have stronger checks in place, but it still pays to lock things down.
The short version
Protect your number
- Set a strong PIN or password on your phone account.
- Turn on two-step verification for your telco account.
- Use authenticator apps or passkeys instead of text codes.
- If your phone suddenly loses service, call your telco from another phone.
How it works
There are two main ways criminals take over a number:
- SIM swap. They convince your telco to move your number to a new SIM card they control, usually by pretending to be you.
- Port-out. They move your number to a different telco in their name.
Either way, your phone loses service and the criminal starts receiving your calls and texts, including security codes. They often already have your password and personal details from phishing or a data breach.
What Australian telcos must do
ACMA rules require telcos to use extra identity checks before transferring a mobile number to another provider, usually by sending a code or confirmation to the existing number. Telcos are also expected to use stronger verification for high-risk requests like SIM swaps. These checks have greatly reduced number theft, and the ACMA has penalised telcos that didn’t follow them. But no system is perfect, so your own protections still matter.
Warning signs
- Your phone suddenly shows “No service” or “SOS only” in a place where it normally works.
- You get a text or email from your telco about a SIM change or port request you didn’t make.
- You can’t make calls or send texts, but Wi-Fi still works.
- You get password reset or sign-in alerts from your bank or email.
Protect your number
Lock your telco account
Set a PIN, password or verbal passphrase on your account so staff must ask for it before making changes. Ask your telco what options it offers.
Secure your telco online account
Use a unique password and turn on two-step verification for your telco’s app or website.
Move important accounts off text codes
Use an authenticator app, passkey or security key for email, banking and anything that offers it. See our two-step verification guide.
Limit what’s public
Your date of birth, address and phone number help criminals pass identity checks. Keep them off public social media profiles.
Set a SIM PIN
A SIM PIN stops someone using your SIM in another phone if your phone is stolen. Find it in your phone’s settings under mobile or cellular settings.
If your phone suddenly loses service
Call your telco from another phone
Ask whether your SIM has been swapped or your number ported. If so, ask them to stop it and restore the number.
Call your bank
Ask them to check for and block unusual transactions while your number is out of your control.
Secure your email
From another device, change your email password and check recovery details and forwarding. See hacked email.
Get support and report it
Contact IDCARE on 1800 595 160, and report to ReportCyber.
Don’t assume it’s a network outage
If your phone loses service unexpectedly and stays that way, especially after a suspicious message, check with your telco straight away. Minutes matter.
Common questions
Can someone swap my SIM without my details?
It’s much harder now with telco verification rules. Criminals usually gather details first from breaches, phishing or social media.
Do eSIMs make this harder or easier?
eSIMs are managed through your telco account, so securing that account is the key protection either way.
Should I stop using text message codes entirely?
Use stronger options wherever they’re offered, and keep text codes only where nothing else is available.
Sources
This guide is general information, not legal or financial advice. If you think you’ve lost money or personal information, contact your bank and the services named above straight away.
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