Taxation Administration Act 1953 (Cth) (TAA 1953
The TAA 1953 provisions protect the TFNs of all entities, including individuals and other entities such as corporations, partnerships, superannuation funds and trusts.
https://www.oaic.gov.au/privacy/privacy-legislation/the-privacy-act/tax-file-numbers
https://www.legislation.gov.au/F2015L00249/latest/text
Privacy (Tax File Number) Rule 2015
This item is authorised by the following title:
The TFN Rule only applies to the TFN information of individuals and does not apply to TFN information about other legal entities such as corporations, partnerships, superannuation funds and trusts.
8. Collection of TFN information
(1) TFN recipients must only request or collect TFN information from individuals and other TFN recipients for a purpose authorised by taxation law, personal assistance law or superannuation law.
(2) When requesting an individual’s TFN, TFN recipients must take reasonable steps to ensure that:
(a) individuals are informed:
(i) of the taxation law, personal assistance law or superannuation law which authorises the TFN recipient to request or collect the TFN
(ii) of the purpose(s) for which the TFN is requested or collected
(iii) that declining to quote a TFN is not an offence
(iv) about the consequences of declining to quote a TFN
(b) the manner of collection does not unreasonably intrude on the individual’s affairs, and
(c) the TFN recipient only requests or collects information that is necessary and relevant to the purpose of collection under applicable taxation law, personal assistance law or superannuation law.
9. TFNs provided incidentally
If an individual provides information to a TFN recipient which includes a TFN, for a purpose not connected with the operation of a taxation law, personal assistance law or superannuation law:
(a) the individual providing the information may remove the TFN, and
(b) if the individual does not remove the TFN, the TFN recipient must not use or disclose the TFN or record the TFN in a way that is inconsistent with the TAA or the TFN Rule.
10. Use or disclosure of TFN information
TFN information must only be used or disclosed (including for matching personal information about individuals) by TFN recipients:
(a) for a purpose authorised by taxation law, personal assistance law or superannuation law, or
(b) for the purpose of giving an individual any TFN information that the TFN recipient holds about that individual.
11. Storage, security and destruction of TFN information
(1) TFN recipients must take reasonable steps to:
(a) protect TFN information from misuse and loss, and from unauthorised access, use, modification or disclosure
(b) ensure that access to records containing TFN information is restricted to individuals who need to handle that information for taxation law, personal assistance law or superannuation law purposes.
(2) A TFN recipient must take reasonable steps to securely destroy or permanently de-identify TFN information where it is no longer:
(a) required by law to be retained, or
(b) necessary for a purpose under taxation law, personal assistance law or superannuation law (including the administration of such law).