Tax file number

A tax file number (TFN) is a unique identifier issued by the Australian Taxation Office (ATO) to each taxpaying entity — an individual, company, superannuation fund, partnership, or trust. Not all individuals have a TFN, and a business has both a TFN and an Australian Business Number (ABN). If a business earns income as part of carrying on its business, it may quote its ABN instead of its TFN.

The TFN was introduced initially to facilitate file tracking at the ATO, but has since been expanded to encompass income and other data matching. The TFN consists of a nine digit number, usually presented in the format nnn nnn nnn. Strict laws require that TFNs may be recorded or used only for specifically authorised tax-related purposes.

The TFN serves a purpose similar to the American Social Security number, but its use is strictly limited by law to avoid the functionality creep which has affected the US counterpart. It also serves a similar function as national insurance in the UK.

TFNs have been used by the ATO since the 1930s. The TFN itself was either 8 or 9 digits, with a check digit. Individuals received a 9 digit TFN and non-individuals received an 8 digit TFN. The quote of the TFN was not obligatory when, for example, lodging a tax return, though failing to quote one may delay the processing of the tax return.

In May 1988, following the demise of the Australia Card scheme, the Treasurer Paul Keating announced that the Government intended to introduce an enhanced TFN scheme, and legislation establishing the scheme was passed that year.

When it was introduced in 1988 the 8 and 9 digit TFN scheme still applied. However, as the 8 digit TFNs were becoming exhausted, all new taxpayers are issued 9 digit TFNs. The numbers now do not have any embedded meaning.

The primary purpose of the expanded TFN system is to allow the ATO to collect income and other information for taxpayers (officially known as "data matching"). This is done by the ATO requiring paying entities (e.g., banks, employers, public companies, superannuation funds, Centrelink and others) to electronically provide the ATO with information of certain types of payments made by them, together with the associated TFN of the recipient. When taxpayers file their income tax returns at the end of the financial year, the ATO can electronically match the income reported by the taxpayer against the payments reported by the paying entities.

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Wikipedia