TL;DR: If your Tax File Number is stolen or misused, call the ATO Client Identity Support Centre on 1800 467 033 (8am–6pm AEST, weekdays). Warning signs include changes to your ATO record you didn’t make (especially bank details), unauthorised myGov access, or a self-managed super fund set up in your name. The ATO will monitor your record and add protections. Also contact IDCARE (1800 595 160) and set up a Strong myID.
Signs your TFN may be compromised
The ATO lists these red flags:
- someone has stolen or misused your TFN, ABN or other tax details;
- someone accessed your myGov account or linked ATO services without permission;
- your ATO record was changed without approval, like your bank account;
- someone set up a self-managed super fund in your name, or changed an existing one, to get at your super.
Common ways TFNs leak: scam calls "from the ATO", fake job onboarding forms, phishing myGov pages, and data breaches.
What to do
- Call the ATO on 1800 467 033 as soon as you can (8am–6pm AEST, Monday–Friday). This is the Client Identity Support Centre; it helps you re-establish your tax identity and tells you which ID documents you’ll need.
- Secure myGov. Change your password, turn on MFA and check sign-in history (guide).
- Set up a Strong myID to protect ATO online access.
- Report other cybercrime via ReportCyber, and identity theft to state or territory police.
- Call IDCARE on 1800 595 160 (free, confidential) if other personal information is exposed.
- Consider a credit ban if your ID documents leaked too.
What the ATO does for you
- Checks your account for unusual activity and corrects details if your TFN was misused.
- Monitors your record before lodgments or claims are processed automatically.
- May contact you to confirm suspicious activity before processing.
- Keeps security measures on your file until it’s satisfied the risk has passed.
Avoid the scam after the scam
Once you’ve reported identity theft, scammers sometimes call "from the ATO" offering to "help". Real ATO contact won’t demand payment by gift card or crypto. If unsure, hang up and call the ATO yourself. Our guide to ATO and myGov scam texts covers the common versions.
Finding your TFN safely (and where not to look)
If you’ve lost your TFN rather than had it stolen, the ATO’s lost or stolen TFN page lists safe places to find it:
- myGov (linked to the ATO) or the ATO app;
- your notice of assessment or other ATO letters;
- your income statement or payment summary from your employer;
- your super account statement;
- your registered tax agent.
Never search for it by replying to a text or email that offers to "look up" your TFN. Those are fishing for exactly this.
If your TFN is stolen or misused, the ATO says to tell it as soon as possible: call the Client Identity Support Centre on 1800 467 033 (8am to 6pm, Monday to Friday). It may add security measures that monitor your account for unusual activity.
Where else is your data?
A TFN rarely leaks alone. A free exposure check shows which breaches your email appears in, which hints at what else is out there.
Frequently Asked Questions
Where can I find my TFN if I’ve lost it?
The ATO says to check myGov or the ATO app, your notice of assessment, ATO letters, your income statement, super statement, or ask your registered tax agent.
What number do I call if my TFN is stolen?
The ATO Client Identity Support Centre on 1800 467 033, 8am to 6pm AEST, Monday to Friday.
How do I know if someone is using my TFN?
Signs include changes to your ATO record you didn’t make, unauthorised myGov access, or a self-managed super fund set up in your name.
What does the ATO do if my TFN is compromised?
It checks for suspicious activity, monitors your record before processing lodgments, may contact you to confirm activity, and keeps security measures on your file.
Should I contact IDCARE about a stolen TFN?
Yes, if other personal information may be compromised. IDCARE is free on 1800 595 160.