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TFN

A Tax File Number is part of everyday tax administration in Australia, but many people are unsure what a TFN actually does, when it is used or whether it changes over time.

This section explains the fundamentals of Australian TFNs in plain language. Explore how TFNs relate to work, tax and other common situations, the difference between a TFN and other identifiers such as an ABN, and what having a TFN means in practice.

For application instructions, workplace-specific questions or problems with an existing TFN, use the dedicated sections of the TFN blog.

Preguntas frecuentes

What is a Tax File Number?
A Tax File Number, or TFN, is an identifier used by the Australian Taxation Office for tax and related administrative purposes. Individuals generally keep the same TFN throughout their life.
Is a TFN the same as an ABN?
No. A TFN identifies a taxpayer for tax administration, while an Australian Business Number is primarily associated with businesses and other entities operating in Australia.
Does my TFN change when I change jobs?
Normally, changing employer does not mean receiving a new TFN. Your existing TFN continues to identify you for tax purposes.
Where can I learn how to apply for a TFN?
Application-specific information belongs in our TFN Application section, where the different application situations can be covered in more detail.