What is a TFN?
A TFN is used to identify tax-related events.
Providing a TFN is optional when creating a Kids Account—learn about your tax options when investing for a kid.
Where do I find a TFN?
If the kid already has a TFN, but you don’t know what it is, you can try:
asking the child to log into their myGov account (if they have one)
checking previously lodged income tax returns.
Kid doesn’t have a TFN?
See the ATO website for more info about applying for a TFN.