Under the Foreign Acquisitions and Takeovers Act 1975, a screening mechanism applies to foreign investments in Australian land which meet specific monetary thresholds.  'Land' includes buildings and subsoil. The applicable monetary thresholds vary depending on the type of land and investor origin. In the case of residential land and vacant commercial land, the screening threshold is $0 for all investors. As for developed commercial land, the general threshold for private investors is at $275 million, but a lower threshold applies to specific "low threshold land" categories and a higher threshold applies for investors from certain countries with which Australia has free trade agreements. In response to the COVID-19 pandemic, the Australian Government temporarily reduced all screening thresholds under the Act to $0 (effective from 18 April 2020) in order to protect the national interest. The prior tiered threshold regime has since been reinstated. For a table of all the applicable thresholds in 2021, see Treasury, "Australia's Foreign Investment Policy" (1 January 2021), Annex 1, p. 16.
A planned land acquisition which meets the threshold test must be notified before the acquisition can take place, and it can be prohibited by the Treasury if considered to be contrary to the 'national interest'. The national interest, and what would be contrary to it, is not defined in the Act or the Foreign Acquisitions and Takeovers Regulation 2015. Assessments are made on a case-by-case basis. However, a Foreign Investment Policy document states that the Government typically considers the following factors when assessing foreign investment proposals: national security; competition; other Australian government policies, including tax; impact on the economy and the community and the character of the investor. In the case of residential land, whether the proposed investment will increase Australia's housing stock is considered.
Certain acquisitions are exempted from reviews by virtue of the 2015 Regulation. Generally, acquisitions by foreign non-government acquirers of an interest in Australian land from the Commonwealth, a State, a Territory or a local governing body of Australia or an entity wholly owned by the Commonwealth, a State, a Territory or a local governing body, are exempted from reviews. However, acquisitions of an interest in Australian land if the interest is, or includes, certain infrastructure assets, are excluded from the exemption. These infrastructure assets include 'public infrastructure', which is defined in the Regulation as including also electricity generation, transmission, distribution and supply systems and facilities.
From 1 January 2021, amendments to the Act and Regulation introduced, among other changes, the possibility to screen certain investments under a narrower 'national security test' when these investments do not meet the monetary and control thresholds of the already existing mechanisms but nonetheless pose national security concerns. All foreign investors must obtain authorisation to acquire an interest in 'national security land', which is defined as defence premises or land in which the Commonwealth, as represented by an agency in the national intelligence community, has an interest that is publicly known or  could be known upon the making of reasonable inquiries. National security land is subject to a $0 screening threshold.
On 1 April 2022, the Foreign Acquisitions and Takeovers Amendment Regulations 2022 came into effect (the Regulations). The Regulations, which amended the Foreign Acquisitions and Takeovers Regulation 2015, clarified certain aspects of the foreign investment review framework and streamlined the process for certain less sensitive types of investment. The Regulations are inter alia intended to reduce the regulatory burden for foreign investors that engage in moneylending, invest in unlisted land entities or Australian media businesses, acquire shares or units under rights issues and other pro-rata offers, or transact on behalf of institutional investors as part of a custodian service (through amendments that refine the rules for the notification of these kinds of foreign investments, including raising thresholds and providing broader exemptions from foreign investment screening). The notification has, for instance, increased the threshold for an investment screening in unlisted Australian land entities from 5% to 10%. The previous 5% threshold was lower than the threshold for investments into national security businesses, despite not entailing the same risks. The change to the threshold was to ensure that the Principal Regulations only capture acquisitions that pose sufficient risks to the national interest to warrant screening.
"4 Dictionary of definitions
 In this Act: [...]
Australian land means agricultural land, commercial land, residential land or a mining or production tenement. [...]
commercial land means land in Australia or the seabed of the offshore area, other than land:
 (a) used wholly and exclusively for a primary production business; or
 (b) on which there is at least one dwelling (except commercial residential premises); or
 (c) on which the number of dwellings (except commercial residential premises) that could reasonably be built is less than the number prescribed by the regulations for the purposes of subparagraph (a)(ii) of the definition of residential land in this section. [...]
foreign person means:
 (a) an individual not ordinarily resident in Australia; or
 (b) a corporation in which an individual not ordinarily resident in Australia, a foreign corporation or a foreign government holds a substantial interest; or
 (c) a corporation in which 2 or more persons, each of whom is an individual not ordinarily resident in Australia, a foreign corporation or a foreign government, hold an aggregate substantial interest; or
 (d) the trustee of a trust in which an individual not ordinarily resident in Australia, a foreign corporation or a foreign government holds a substantial interest; or
 (e) the trustee of a trust in which 2 or more persons, each of whom is an individual not ordinarily resident in Australia, a foreign corporation or a foreign government, hold an aggregate substantial interest; or
 (f) a foreign government; or
 (g) any other person, or any other person that meets the conditions, prescribed by the regulations.[...]
land includes:
 (a) a building (including a new dwelling or an established dwelling) or a part of a building; and
 (b) subsoil of land.[...]
residential land:
 (a) means land in Australia if:
 (i) there is at least one dwelling on the land; or
 (ii) the number of dwellings that could reasonably be built on the land is less than the number prescribed by the regulations; and
 (b) does not include land:
 (i) used wholly and exclusively for a primary production business; or
 (ii) on which the only dwellings are commercial residential premises.
residential land acquisition means a notifiable action to acquire an interest in residential land.
[...]
12 Meaning of interest in Australian land
 (1) An interest in Australian land (however described) is:
 (a) a legal or equitable interest in Australian land, other than:
 (i) an interest under a lease or licence or in a unit in a unit trust; or
 (ii) an interest in an agreement giving a right (known as a profit à prendre) to take something off another person's land, or to take something out of the soil of that land; or
 (iii) an interest in an agreement involving the sharing of profits or income from the use of, or dealings in, Australian land; or
 (b) an interest in a security in an entity that owns Australian land, being a security that entitles the holder to a right to occupy a dwelling of a kind known as a flat or home unit situated on the land; or
 (c) an interest as lessee or licensee in a lease or licence giving rights to occupy Australian land if the term of the lease or licence (including any extension or renewal) is reasonably likely, at the time the interest is acquired, to exceed 5 years; or
 (d) an interest in an agreement giving a right of a kind mentioned in subparagraph (a)(ii) if the term of the agreement (including any extension or renewal) is reasonably likely, at the time the interest in the agreement is acquired, to exceed 5 years; or
 (e) an interest in an agreement involving the sharing of profits or income from the use of, or dealings in, Australian land if the term of the agreement (including any extension or renewal) is reasonably likely, at the time the interest in the agreement is acquired, to exceed 5 years; or
 (f) an interest in a share in an Australian land corporation or agricultural land corporation; or
 (g) an interest in a unit in an Australian land trust or agricultural land trust; or
 (h) if the trustee of an Australian land trust or agricultural land trust is a corporation—an interest in a share in that corporation.
 (2) An interest is an interest in Australian land even if it is the only interest that exists in the land or other thing concerned.
 (3) A person acquires an interest in Australian land even if:
 (a) the person has previously acquired an interest in Australian land; or
 (b) the interest is an increase in the amount of an existing interest of the person in Australian land.
[...]
43 Meaning of significant action—land
 An action is a significant action if:
 (a) the action is for a foreign person to acquire an interest in Australian land; and
 (b) the threshold test is met in relation to the land (see Subdivision B of Division 4).
[...]
45 Actions that are not significant actions—exemption certificates
 (1) Despite this Division, an action is not a significant action if:
 (a) the action is a foreign person acquiring an interest in a new dwelling that will be, is being or has been built on another interest (the development interest) in Australian land; and
 (b) the acquisition was from a person who was specified in an exemption certificate in force under section 57; and
 (c) the development interest was specified in the certificate; and
 (d) the specified person provided the foreign person with a copy of that certificate before the foreign person acquired the interest; and
 (e) either:
 (i) the conditions (if any) specified in the certificate were met; or
 (ii) the foreign person is not, at the time of the action, aware that one or more of the conditions specified in the certificate have not been met.
 [...]
47 Meaning of notifiable action—general
 (1) An action is a notifiable action if the conditions in this section are met.
First condition—kinds of action
 (2) The first condition is that the action is any of the following:  [...]
 (c) to acquire an interest in Australian land.
Second condition—threshold
 (3) The second condition is that the threshold test is met in relation to the entity, business or land (see Subdivision B of Division 4).[ ...]
Last condition—action taken by a foreign person
 (5) The last condition (whether paragraph (2)(a), (b) or (c) applies) is that the action is or is to be taken by a foreign person.
[...]
49 Actions that are not notifiable actions—exemption certificates
 (1) Despite this Division, an action is not a notifiable action if:
 (a) the action is a foreign person acquiring an interest in Australian land; and
 (b) the action would not be a significant action under section 45 (actions that are not significant actions—exemption certificates).
 (2) The regulations may provide, in relation to exemption certificates in force under regulations made for the purposes of section 63, that an action of a specified kind is not a notifiable action.
[...]
52 The threshold test for land
Land without threshold value
 (1) The threshold test is met in relation to land if the land is of a kind that is prescribed by the regulations for the purposes of this subsection.[...]
Other land where value of interest is above threshold value
 (3) The threshold test is met in relation to land if both of the following apply:
 (a) the land is not land prescribed for the purposes of subsection (1) or agricultural land;
 (b) the value of the interest in the land is more than the value prescribed for the purposes of this paragraph.
[...]
55B Meaning of notifiable national security action
 (1) An action is a notifiable national security action if the action is taken, or proposed to be taken, by a foreign person and the action is any of the following:[...]
 (d) to acquire an interest in Australian land that, at the time of acquisition, is national security land;
 (e) to acquire a legal or equitable interest in an exploration tenement in respect of Australian land that, at the time of acquisition, is national security land.
 (2) For the purposes of paragraph (1)(e), a person acquires a legal or equitable interest in an exploration tenement even if:
 (a) the person has previously acquired an interest in an exploration tenement; or
 (b) the interest is an increase in the amount of an existing interest of the person in an exploration tenement.
 (3) The regulations may provide, in relation to exemption certificates in force under regulations made for the purposes of section 63, that an action of a specified kind is not a notifiable national security action.
[...]
55F Meaning of reviewable national security action—land
 An action is a reviewable national security action if:
 (a) the action is taken, or proposed to be taken, by a foreign person and the action is to acquire an interest in Australian land; and
 (b) the action is or was not otherwise a significant action, a notifiable action or a notifiable national security action.
[...]
66A National security review of actions
Review allowed if action may pose a national security concern
 (1) Subject to subsection (5), the Treasurer may review:
 (a) a reviewable national security action; or
 (b) a significant action that is not a notifiable action or notifiable national security action;
if the Treasurer considers that the action may pose a national security concern.
[...]
67 Order prohibiting proposed actions
 (1) The Treasurer may, by notifiable instrument, make an order under subsection (2) if the Treasurer is satisfied that:
 (a) a significant action (other than a significant action covered by subparagraph (1A)(a)(ii)) is proposed to be taken; and
 (b) taking the significant action would be contrary to the national interest.
 (1A) The Treasurer may, by notifiable instrument, make an order under subsection (2) if the Treasurer is satisfied that:
 (a) an action of any of the following kinds is proposed to be taken:
 (i) a notifiable national security action that is not a significant action;
 (ii) an action in respect of which the Treasurer has given a notice under subsection 66A(4);
 (iii) a reviewable national security action notified to the Treasurer; and
 (b) taking the action would be contrary to national security.
 (2) The Treasurer may make an order in accordance with the following table.
[see legal source for table]
[...]
81 Compulsory notice of notifiable actions and notifiable national security actions
 (1) A foreign person who proposes to take a notifiable action or notifiable national security action (other than because of the operation of section 18A (increasing percentage of interests without acquiring additional interests in securities)) must give a notice to the Treasurer before taking the action.
 (1A) A foreign person who takes a notifiable action or notifiable national security action because of the operation of section 18A (increasing percentage of interests without acquiring additional interests in securities) must give a notice to the Treasurer before the end of 30 days after the action is taken.
 (2) If a person takes an action by entering an agreement, the notice must deal with each notifiable action or notifiable national security action covered by the agreement.[...]" (Foreign Acquisitions and Takeovers Act 1975 (Act No. 92 of 1975), last amended by Australia's Foreign Relations (State and Territory Arrangements) (Consequential Amendments) Act 2020 on 1 January 2021, Sections 4, 12, 43, 45, 47, 49, 52, 55B, 55F, 66A, 67 and 81)
-------------------------
"5 Definitions
 In this instrument: [...]
national security land means:
 (a) defence premises (within the meaning of section 71A of the Defence Act 1903, excluding subparagraph (a)(iii) of the definition of that expression); or
 (b) land in which the Commonwealth, as represented by an agency in the national intelligence community, has an interest that:
 (i) is publicly known; or
 (ii) could be known upon the making of reasonable inquiries.[...]
vacant:
 (a) land is vacant if there is no substantive permanent building on the land that can be lawfully occupied by persons, goods or livestock; but
 (b) despite paragraph (a), land is not vacant if a wind or solar power station is located on the surface of the land.
[...]
Division 3—Exemptions for certain actions from being significant and notifiable actions
28 Application of this Division
(1) This Division applies to the provisions of the Act, other than:
 (a) the definition of foreign person in section 4 of the Act; and
 (b) any other provision of the Act to the extent that it relates to that definition.
The provisions of the Act that this Division applies to are the excluded provisions.
(2) This Division does not apply in respect of an action that is a reviewable national security action.
[...]
31 Australian businesses carried on by or land acquired from government
 (1) The excluded provisions do not (subject to subsection (2)) apply in relation to an Australian business that is carried on (whether alone or together with one or more other persons) by, or an acquisition of an interest in Australian land from, any of the following persons:
 (a) the Commonwealth, a State, a Territory or a local governing body;
 (b) a body corporate established for a public purpose by or under a law of the Commonwealth, a State or a Territory;
 (c) an entity wholly owned by the Commonwealth, a State, a Territory, a local governing body or a body corporate covered by paragraph (b).
 (2) However, subsection (1) does not apply in relation to:
 (a) an acquisition of an interest by a foreign government investor; or
 (b) an acquisition of an interest in Australian land if the interest is, or includes, an interest in any of the following infrastructure:
 (i) public infrastructure, except in relation to public roads;
 (ii) infrastructure for existing or proposed roads, existing or proposed railways, or existing or proposed inter‑modal transfer facilities, within the National Land Transport Network (within the meaning of the National Land Transport Act 2014);
 (iii) infrastructure for existing or proposed roads, existing or proposed railways, or existing or proposed inter‑modal transfer facilities, that are designated under a law of a State or Territory as either significant or controlled by the State or Territory;
 (iv) the infrastructure (or part of the infrastructure) of a telecommunications network;
 (v) a nuclear facility; or
 (c) an acquisition of an interest in Australian land that, at the time of the acquisition, is national security land; or
 (d) an Australian business the assets of which include:
 (i) an interest in Australian land to which paragraph (b) or (c) applies; or
 (ii) a legal or equitable interest in an exploration tenement in respect of Australian land that, at the time the relevant action is taken in relation to the Australian business, is national security land; or
 (e) an Australian business that is a national security business.
[...]
37  Acquisition in certain circumstances [amended in 2022]
(1)  The excluded provisions do not apply in relation to an acquisition of an interest in Australian land by a foreign person if a subsection of this section applies in relation to the acquisition. [...]
(4)  All of the following apply: [...]
(c)  after the acquisition, the foreign person, alone or together with one or more associates, holds an interest of less than 10% in the land entity;
[...]
38 Acquisitions of interests in residential land
 (1) The excluded provisions do not apply in relation to an acquisition of an interest in residential land by a foreign person if a subsection of this section applies in relation to the acquisition.
Acquisitions by persons with connection to Australia
 (2) The foreign person meets any of the following conditions:
 (a) the foreign person is, at the time of acquisition, the holder of a permanent visa (within the meaning of the Migration Act 1958);
 (b) the foreign person is, at the time of acquisition, the holder of a special category visa (within the meaning of that Act);
 (c) if the foreign person had entered Australia lawfully immediately before the acquisition, he or she would have been entitled to the grant, on presentation of a passport, of a special category visa (within the meaning of that Act);
 (d) the foreign person is an Australian corporation and would not be a foreign person if interests held directly in it by any one or more of the following persons were disregarded:
 (i) a person to whom any of paragraphs (a), (b), (c) and (e) applies;
 (ii) a person to whom any of paragraphs 35(1)(a) to (c) applies;
 (iii) a person covered by a previous application of this paragraph;
 (e) the foreign person is the trustee of a resident trust at the time of the acquisition, and would not be a foreign person if interests held directly in it by any one or more of the following persons were disregarded:
 (i) a person to whom any of paragraphs (a) to (d) of this subsection applies;
 (ii) a person to whom any of paragraphs 35(1)(a) to (c) applies;
 (iii) a person covered by a previous application of this paragraph.
Acquisitions of interests in residential land by spouses and de facto partners of Australian citizens etc.
 (3) Both of the following apply:
 (a) the person is the spouse or de facto partner (within the meaning of the Acts Interpretation Act 1901) of:
 (i) a person who is, at the time of acquisition, an Australian citizen; or
 (ii) a person who is, at the time of acquisition, the holder of a permanent visa (within the meaning of the Migration Act 1958); or
 (iii) a person who is, at the time of acquisition, the holder of a special category visa (within the meaning of that Act); or
 (iv) a person who, if the person had entered Australia lawfully immediately before the acquisition, would have been entitled to the grant, on presentation of a passport, of a special category visa (within the meaning of that Act);
 (b) the interest is held by the person and his or her spouse or partner as joint tenants.
Acquisitions of interests in residential timeshare schemes
 (4) Both of the following apply:
 (a) the acquisition is of an interest in a timeshare scheme that relates to residential land;
 (b) the foreign person's total entitlement, alone or together with one or more associates, under the timeshare scheme to access the land is no more than 4 weeks in any year.
Acquisition of interests in residential land used for residential care, retirement villages and certain forms of student accommodation
 (5) All of the following apply:
 (a) the land is used for:
 (i) premises that provide for residential care; or
 (ii) a retirement village; or
 (iii) premises that provide accommodation to students in connection with an education institution that is not a school;
 (b) the foreign person is not a foreign government investor;
 (c) the value of the land acquired is less than:
 (i) if the land is covered by paragraphs 52(6)(b) and (c)—the value prescribed by item 3 of the table in subsection 52(5); or
 (ii) otherwise—the value prescribed by item 4 of the table in subsection 52(5).
Certain acquisition of interests in residential land used as retirement villages
 (6) All of the following apply:
 (a) the foreign person has an existing interest in the land;
 (b) the land is used for a retirement village that the foreign person owns;
 (c) the foreign person increases their existing interest in the land by acquiring an interest in a dwelling contained in the retirement village.
[...]
52 Land
Land without threshold value
 (1) For subsection 52(1) of the Act, the following land is prescribed:
 (a) residential land, except residential land covered by subsection (2) of this section;
 (b) commercial land that is vacant;
 (c) a mining or production tenement, except a tenement being acquired by a relevant agreement country investor;
 (d) land (including land otherwise covered by subsection (4) or (5) of this section) acquired by a foreign government investor;
 (e) land held by an Australian land corporation or the trustee of an Australian land trust (except an agricultural land corporation or an agricultural land trust) if:
 (i) the interest in Australian land that is acquired by a foreign person is an interest in a share in the corporation or a unit in the trust; and
 (ii) the land is not covered by subsection (3) of this section.
Residential land not covered by subsection (1)
 (2) Residential land is covered by this subsection if:
 (a) the land is also commercial land that is not vacant; and
 (b) the area of land that is residential land (excluding any commercial residential premises) is less than 10% of the total area of the land; and
 (c) the value of the land that is residential land (excluding any commercial residential premises) is less than 10% of the total value of the land; and
 (d) a reasonable assessment of the area and value of the land was made in determining that the land is covered by paragraphs (b) and (c). [...]
Threshold value for any other land
 (5) The following table prescribes values for paragraph 52(3)(b) of the Act (any other land).
[see legal source for table][...]" (Foreign Acquisitions and Takeovers Regulation 2015 (SLI 2015 No. 217), last amended by Foreign Acquisitions and Takeovers Amendment Regulations 2022 on 31 March 2022)
Foreign Acquisitions and Takeovers Act 1975 (Act No. 92 of 1975), last amended by Australia's Foreign Relations (State and Territory Arrangements) (Consequential Amendments) Act 2020 on  1 January 2021, Sections 4, 12, 43, 45, 47, 49, 52, 55B, 55F, 66A, 67 and 81
Foreign Acquisitions and Takeovers Regulation 2015 (SLI 2015 No. 217), last amended by Foreign Acquisitions and Takeovers Amendment Regulations 2022 on 31 March 2022
[<a href="https://www.legislation.gov.au/Details/C2021C00022/Html/Text">Act</a>],[<a href="https://www.legislation.gov.au/Details/F2021C00062">Reg</a>],[<a href="https://www.legislation.gov.au/Details/F2022L00465">Amendment</a>],[<a href="https://foreigninvestment.gov.au/investing-in-australia/foreign-investment-framework">Other</a>],[<a href="https://www.legislation.gov.au/Details/F2022L00465/Explanatory%20Statement/Text">Other</a>],[<a href="https://foreigninvestment.gov.au/guidance">Other</a>]