A high profile decision from the UK Supreme Court this week, For Women Scotland Ltd v The Scottish Ministers [2025] UKSC 16 (16 April 2025) (“FWS“), holds that the word “sex” as used in the UK anti-discrimination legislation the Equality Act 2010 (UK) (“the EA 2010”), means biological sex, and that the term does not change its meaning in relation to those who have obtained a gender recognition certificate (“GRC”) under the Gender Recognition Act 2004 (UK) (“the GRA 2004”). In the circumstances of this case, this meant that where a “quota” had been established for certain governance roles requiring 50% of non-executive members to be women, that quota could not be met by including those with an “acquired gender” of female due to their holding a GRC.

But the ramifications of the decision go far beyond the specific quota legislation. The question that the court had to address was whether references to “sex”, “women” and “men” in the EA 2010 included those who held GRC’s and had an “acquired” or “certificated” sex. After an extensive review of the general provisions of the discrimination law, the court unanimously concluded that a GRC did not have the effect of deeming someone to have changed their sex for the purposes of the EA 2010.

As they sum up near the end of the decision, at [265] item (xviii):

The meaning of the terms “sex”, “man” and “woman” in the EA 2010 is biological and not certificated sex. Any other interpretation would render the EA 2010 incoherent and impracticable to operate. 

As they point out, this does not remove other protections provided by the EA 2010 to transgender persons, whether or not they hold a GRC. But the ruling will have the effect that it will be possible to establish rules requiring that single-sex spaces such as changing rooms, bathrooms, and other areas designed for the use of one sex, can be reserved for those who have that biological sex and will not have to be made available to those who have the relevant sex through a GRC or claim to be of that sex on some other ground (see references to those issues in para [265] items (xiv) and (xv).)

While the decision itself does not refer to religious belief issues, the case will have important implications for religious groups whose conviction is that a person’s sex is that given at conception biologically, and cannot be later changed by other processes. (For a recent careful and scholarly analysis of the Christian perspective on these issues, see Robert S Smith, The Body God Gives (Lexham Academic, 2025), esp Part 3.) In the UK, those groups will be able to apply this view in the way that they provide services for men or women, or for girls or boys, in accordance with their faith commitments.

Of course the decision is not directly relevant to the law of Australia. But in this post I want to briefly compare the reasoning of the UK Supreme Court in its consideration of the EA 2010, with how a court in Australia might approach similar issues under Australian law, in particular in relation to the federal Sex Discrimination Act 1984 (Cth) (“SDA 1984”). Readers of this blog may recall that we have had a decision of a single judge commenting on some of these issues in the Tickle v Giggle litigation, which I previously suggested was wrongly decided. The reasoning of the Supreme Court of the UK here strongly supports my view that comments about the meaning of the category of “sex” made by the judge in that case were incorrect and should not be supported on appeal. (For an excellent overview of the FWS decision by a UK legal scholar cited by the court, see Michael Foran, “Sex has always meant biological sex“.)

The Australian decision: Tickle v Giggle

I provided a detailed analysis of the decision in  Tickle v Giggle for Girls Pty Ltd (No 2) [2024] FCA 960 (23 August 2024) in a previous post . But by way of a brief reminder: the decision, of Bromwich J in the Federal Court of Australia, found that the company Giggle for Girls Pty Ltd had been guilty of indirect gender identity discrimination when its director, Sall Grover (who was also sued), had removed Roxy Tickle (“the applicant”) from her women-only social media app. Roxy Tickle was born male but had obtained an official updated Queensland birth certificate, issued under the Births, Deaths and Marriages Registration Act 2003 (Qld) (“Qld BDM Registration Act”), as being of the female sex.  This followed from “sexual reassignment surgery”, as defined in the Qld BDM Registration Act.

Giggle and Ms Grover accepted that the app was “discriminatory” on the basis of sex, in the sense of being offered only to women and not men, which formally breached s 5 of the SDA when read with s 22. However, Giggle relied on another provision of the legislation, s 7D, to excuse this, saying that provision of a special service for women could be justified as a “special measure” to deal with hardships experienced by women (here, having to deal with the well-known fact of harassment of women on social media by men).

The claim by the applicant was a claim of “gender identity discrimination”, not “sex discrimination” as such. Indeed, the applicant strongly resisted any suggestion that sex discrimination was the issue, arguing that they had not been excluded from the app because of a male identity- see para [54]. Given this basis for the claim, all that Bromwich J needed to decide was whether the definition of “gender identity” discrimination had been satisfied. His Honour did not need to formally address the meaning of “sex” for the purposes of the SDA to decide that question.

Indeed, he acknowledged this:

[62] I also accept the Commissioner’s submission in substance to the effect that I do not need to determine the metes and bounds of the meaning of sex in these reasons. I need go no further than accept, as I do, that it is legally sufficient that Ms Tickle is recorded as female on her updated Queensland birth certificate for her to be, at law, of the female sex. (emphasis added)

While the first sentence of this paragraph is correct, with respect, the second sentence is not necessary. His Honour did not need to rule that the applicant was “of the female sex”, to determine the question whether there was “gender identity discrimination”. The definition of that term in s 4 of the SDA provides:

“gender identity” means the gender-related identity, appearance or mannerisms or other gender-related characteristics of a person (whether by way of medical intervention or not), with or without regard to the person’s designated sex at birth.

Hence in order to determine a claim based on “gender identity” discrimination, all that needs to be shown is that some form of detrimental treatment was given to someone on the basis of that person’s “gender-related identity, appearance or mannerisms”. Establishing such discrimination need not involve any finding that the complainant is, or is not, of a particular sex. In these circumstances, the evidence showed that the applicant had been excluded from use of the app because their appearance suggested that they were male, rather than female. That on its own would be perfectly adequate as a ground for gender identity discrimination.

The reason for stressing this point is that the decision cannot serve as a binding legal precedent for the proposition that “sex” is variable under the SDA, as the comments of Bromwich J to this effect were clearly obiter dicta, rather than forming part of the ratio of the case. (This is a well established part of the law governing the way that cases provide precedents for future cases. Comments made by a judge “by the way” in coming to a decision, but which do not form part of the legal reasons necessary for the decision, are classified as obiter and are not binding on other courts.)

In addition to comments on this topic not being binding on other courts, I noted in my former post why in fact his Honour was wrong to say that previous higher-level authority in Australia had established the view that sex was “changeable” as a general proposition. As I said:

In any event, with respect, his Honour’s comments that “sex, as it is deployed in the SDA, … is changeable and not necessarily binary” (at [59]) are not well supported by the authority he cites. He refers to three cases which, it is claimed, demonstate a “30 year history” of sex being changeable. Yet in 2 of the 3 decisions cited this was not a necessary part of the court’s decision, and in the other one the views expressed have not been supported by the High Court of Australia.

I won’t repeat my analysis of the cases here, except to remind readers that on the one occasion when the High Court (the ultimate appellate authority in Australia) was asked to consider issues of this nature, it (apparently deliberately) did not mention the one Federal Court decision that might be said to support the view that sex can be changed:

In a case where perhaps some comment might have been expected, the appeal in NSW Registrar of Births, Deaths and Marriages v Norrie [2014] HCA 11 involving the question whether the NSW Parliament had authorised the Registrar to enter a category of “non-specific” sex on a birth certificate, the High Court simply noted in passing that the implications of this finding may be relevant to marriage- but offered no views as to how that might be resolved; see para [42]:

The chief, perhaps the only, case where the sex of the parties to the relationship is legally significant is marriage, as defined in the fashion found in s 5(1) of the Marriage Act 1961 (Cth) (In the Marriage of C and D (1979) 28 ALR 524; Bellinger v Bellinger [2003] UKHL 21;  [2003] 2 AC 467 at 483 [58].)

It is worth noting that in its final cross-references in that quote, the High Court referred to older cases denying that a transsexual person could be legally regarded as of their “reassigned” gender for the purposes of marriage, but made no comment about the decision in Kevin, which had explicitly declined to follow precisely those two earlier decisions. So it is still not clear whether Kevin represents the law of Australia.

To sum up: comments by Bromwich J on the changeability of sex were not necessary for the decision, and in any event are likely to be wrong. I also spelled out previously why I thought his Honour’s other finding, on the gender identity discrimination claim, was incorrect. The claim was based on what is called “indirect” gender identity discrimination, under s 5B(2) of the SDA. To sum up, such a claim is based on the imposition of “a condition, requirement or practice that has, or is likely to have, the effect of disadvantaging persons who have the same gender identity as the aggrieved person.” Here, the relevant “requirement” was described by Bromwich J at [134] as “needing to appear to be a cisgendered female in photos submitted to the Giggle App”.

It seems to be true that imposition of a requirement of this sort (that the photograph submitted was that of a biological female person) would “disadvantage” persons who were biologically male but intending to present as female. But there are two other key features of the SDA 1984 relevant to s 5B(2) which I argue that Bromwich J did not properly take into account. One was that there is an explicit exception to that provision, spelled out in s 7B: “if the condition, requirement or practice is reasonable in the circumstances”. I argue that it was perfectly reasonable to set up a females-only app restricted to biological women, taking into account the circumstances including clear evidence of harassment of women on the internet.

The second exception to the operation of s 5B(2) is found in s 7D of the Act. In clear terms, s 7D(2) says that there can be no action taken under s 5B where what has been done amounts to a “special measure” to account for circumstances applying to women.

Section 7D(2) explicitly says that:

7D(2) A person does not discriminate against another person under section 5, 5A, 5B, 5C, 6, 7, 7AA or 7A by taking special measures authorised by subsection (1).

This seems to mean that, whenever there is a practice that satisfies any one of the paragraphs of s 7D(1), (here s 7D(1)(a), a special measure to achieve equality between men and women) it cannot be regarded as discriminatory under any of the listed provisions in s 7D(2), which includes s 5B (the gender identity discrimination provision). While each of the various paragraphs in s 7D(1) lists an area of discrimination under the Act as to which the defence of “special measures” will apply, s 7D(2) does not as drafted “distribute” those defences among the various prohibitions. So a “special measure” to redress practical inequality between men and women under s 7D(1)(a), seems to provide a good defence to any of the provisions listed in s 7D(2), among which is the prohibition on “gender identity” discrimination in s 5B. As I noted, this powerful argument was dismissed far too quickly by Bromwich J at para [86] as “unworkable and nonsensical”. With respect, it is neither, and it is certainly not so absurd as to justify a judge “redrafting” the provision to represent his view of what Parliament should have done.

Applying the logic of FWS to the meaning of sex under the SDA 1984

So- to return to the question posed above: does the logic of the UK FWS decision provide guidance for future courts in Australia dealing with similar issues? I think it does, for the following reasons. Let’s consider the question whether the words “sex”, “woman” and “man” are referring to the biological meaning of those words in the SDA 1984 (the Australian sex discrimination legislation).

I take some of the reasons in FWS provided by Lord Hodge at para [265] (summarising the court’s approach), to see how they might apply to the Australian situation.

[265] (ii) Parliament in using the words “man” and “woman” in the SDA 1975 referred to biological sex.

The reference here to the “SDA 1975” is to the previous UK legislation dealing with sex discrimination. In Australia, too, it seems fairly obvious that in 1984 Parliament would have given a biological meaning to the words being discussed here. At that stage there was no separate prohibited ground relating to gender identity. Indeed, the 1984 Act was clearly based on a UN Convention, the Convention on the Elimination of All Forms of Discrimination Against Women done at New York on 18 December 1979 ([1983] ATS 9) (“CEDAW”). When the SDA 1984 was enacted, s 9(10) of the legislation referred to CEDAW as the main source enlivening the validity of the law under the external affairs power. CEDAW remains a part of the SDA, reproduced in full in the Schedule to the Act.

Bromwich J at [70] notes that later the range of external treaties supporting the law was expanded. But the provisions of CEDAW remain at the heart of the legislation. That convention explicitly refers to the rights of “women”- it is not a general “sex discrimination” treaty. There can of course be a debate about whether CEDAW protects the right of “transgender women”, and Bromwich J surveys that debate but in the end does not find it necessary to decide whether it does or not, as even if it did, it would not have supported the applicant’s case here- see paras [178]-[180]. The applicant was not complaining that they had been treated detrimentally as compared to men, but rather in relation to what they claimed were another specific class of women.

So CEDAW, even if applicable, was not directly relevant. But it should be noted that CEDAW contains a number of provisions relating to pregnancy and maternity, which it can be argued clearly assume that the protected class of persons are biological women. See for example art 4(2) “protecting maternity”, art 11(2) referring to pregnancy and maternity leave, art 12(2) referring to “pregnancy, confinement and the post-natal period, granting free services where necessary, as well as adequate nutrition during pregnancy and lactation”. In other words, there are very good reasons to see that the words “sex” and “women” referred to biological realities in the SDA as initially enacted.

[265](iv) The GRA 2004 did not amend the meaning of “man” and “woman” in the SDA 1975.

Here Lord Hodge in FWS notes that the UK legislation allowing “gender reassignment” did not directly amend the definitions of “man” and “woman” in the SDA 1975, the sex discrimination legalisation then in force.

The Australian situation is more complex. One might see here something contrary to the UK experience, because when the category of “gender identity discrimination” was added to the SDA 1984, in 2013 (by the Sex Discrimination Amendment (Sexual Orientation, Gender Identity and Intersex Status) Act 2013 (Cth) (the “2013 SDA Amendment”)), at the same time and by that amending Act, the definitions of “man” and “woman” were repealed (see comment by Bromwich J at para [59]).

However, it may be noted that while these definitions were removed, they were not replaced by any explicit provision expanding the definition of the terms to include transitioned gender of any sort. Instead, whatever Parliament thought it was doing, the effect was to simply leave the terms to have their common law meaning. What this is, is still a matter to be settled by high authority in Australia. As noted above, in one of the very rare comments on the issue from the High Court, that court referred to decisions holding that sex refers to biological sex and is not changeable: In the Marriage of C and D (1979) 28 ALR 524; Bellinger v Bellinger [2003] UKHL 21;  [2003] 2 AC 467 at 483 [58].

[265] (vi) The context in which the EA 2010 was enacted was therefore that the SDA 1975 definitions of “man” and “woman” referred to biological sex and trans people had the protected characteristic of gender reassignment. 

Similarly, in Australia, even after 2013 when “gender identity discrimination” was introduced into the SDA 1984, the Act continued to provide protection on the basis of “sex” (that term had not been redefined in any way), and for the reasons noted above this meant biological sex.

[265] (viii) It is important that the EA 2010 is interpreted in a clear and consistent way so that groups which share a protected characteristic can be identified by those on whom the Act imposes obligations so that they can perform those obligations in a practical way.

This important point is discussed in more detail in FWS at paras [151]-[154]. It is particularly relevant to the concept of indirect discrimination. Lord Hodge notes that this concept accepts that

[153] … people who share a particular protected characteristic (known or perceived) often have common experiences or needs, whether arising from differences of biology or physiology, or societal expectations or structures affecting their group. These shared experiences or needs can and do give rise to particular disadvantage if they are not met, and they differentiate that group from other groups without the protected characteristic. As we have said, the duties imposed by the EA 2010 require an ability to anticipate that particular rules, policies or practices might affect those who share a protected characteristic and have distinct needs or interests in consequence. 

This need also arises in the Australian context, because the prohibition against indirect discrimination, such as in s 5B(2) of the SDA, requires an approach which considers whether or not “a condition, requirement or practice that has, or is likely to have, the effect of disadvantaging persons” who have the same protected characteristic as the aggrieved person. But to make a judgment on that issue, and to assess what is “likely”, the protected group needs to broadly share certain relevant characteristics. In the case of sex, there are certain clearly recognised issues which arise connected to female biology. Matters relating to menstruation, child-bearing, breast-feeding and menopause, for example, are relevant to those who are biologically female. To add to the protected group those who are not biologically female will unduly confuse duties under the law and make the legislation incoherent.

[265] (x) Interpreting “sex” as certificated sex would cut across the definitions of “man” and “woman” and thus the protected characteristic of sex in an incoherent way. It would create heterogeneous groupings. As a matter of ordinary language, the provisions relating to sex discrimination, and especially those relating to pregnancy and maternity (sections 13(6), 17 and 18), and to protection from risks specifically affecting women (Schedule 22, paragraph 2), can only be interpreted as referring to biological sex (paras 172, 177-188). 

The point here is equally valid for the SDA 1984. A number of provisions in the legislation refer to sex in a way which clearly signals a biological reference. For example, there are exceptions to the prohibition against “sex discrimination” listed in s 30(2), which justify the exceptions based on a range of issues such as the need “to preserve decency or privacy because they involve the fitting of clothing for persons of that sex”- para (c), or the searching of bodies- para (d), or activities in a lavatory- para (e), or “the occupant of the position is required to enter areas ordinarily used only by persons of the relevant sex while those persons are in a state of undress”- para (g). These all assume in normal parlance that it is inappropriate for people of one sex to be involved in spaces where people of the other sex will be naked or otherwise exposed to unwanted attention.

There are a number of other provisions of the SDA 1984 which operate on a biological assumption about sex- see for example s 32 where it is assumed that the meaning of “the provision of services the nature of which is such that they can only be provided to members of one sex”, will be understood by persons making such decisions. It is mainly biology which will determine the nature of such services (such as a cervical swab or prostate test.) Section 42 allows decisions based on sex to turn in part on whether “the strength, stamina or physique of competitors is relevant”, all of which are clearly impacted by biology.

Perhaps s 31 is one of the most striking:

Pregnancy, childbirth or breastfeeding

    Nothing in Division   1 or 2 renders it unlawful for a person to discriminate against a man on the ground of his sex by reason only of the fact that the first – mentioned person grants to a woman rights or privileges in connection with pregnancy, childbirth or breastfeeding.

Here we see that there is a clear biological difference at issue, and a “man” may not complain that benefits are given to a “woman” connected with issues flowing from female biology.

[265] (xiv) There are other provisions whose proper functioning requires a biological interpretation of “sex”. These include separate spaces and single-sex services (including changing rooms, hostels and medical services), communal accommodation and others (paras 210-228); (xv) Similar incoherence and impracticability arise in the operations of provisions relating to single-sex characteristic associations and charities, women’s fair participation in sport, the operation of the public sector equality duty, and the armed forces (paras 229-246). 

The FWS decision explains that the provision of single-sex services requires a biological understanding of the “sex” category. They note the need for such services at para [211]:

“These provisions are directed at maintaining the availability of separate or single spaces or services for women (or men) as a group – for example changing rooms, homeless hostels, segregated swimming areas (that might be essential for religious reasons or desirable for the protection of a woman’s safety, or the autonomy or privacy and dignity of the two sexes) or medical or counselling services provided only to women (or men) – for example cervical cancer screening for women or prostate cancer screening for men, or counselling for women only as victims of rape or domestic violence.”

The Australian SDA provision allowing such services is, as noted previously, s 7D of the SDA 1984. Common sense reasons for the establishment of such services (for example, that most women and girls would prefer not to be sharing facilities with men in states of undress) would be undermined if “sex” were not given its ordinary biological meaning. As the FWS court says at [224] , any other view would “undermine the very considerations of privacy and
decency between the sexes both in the availability of communal sleeping accommodation
and in the use of sanitary facilities”. It will be noted that these very concepts, decency or privacy, are set out in s 30(2)(c) of the SDA 1984.

Conclusion

To conclude this overlong post- the FWS decision is a sensible interpretation of the UK discrimination legislation, the EA 2010, and the logic of the decision seems applicable to the Australian SDA 1984. Where the words “sex”, “woman” or “man” are used there, they refer to a person’s biological identity which is not changeable. I have noted above why in my view the contrary view expressed in the Tickle v Giggle decision was wrong, and in any event is not binding, as it was not part of the ratio of the decision.

In fact, as also noted previously, in my view the Tickle v Giggle decision should be overturned simply on the basis that s 7D(2) of the SDA 1984 explicitly provides that “special measures” such as the establishment of a females-only social media space, cannot be challenged as “gender identity discrimination” under s 5B of the Act. If that is the ground for an appeal, the appeal court may not consider it necessary to discuss the wider question of the meaning of “sex”. But if it does (and this seems to be an issue on which authoritative guidance is important), it is to be hoped that the court will pay close attention to the highly persuasive reasons offered by the FWS decision.

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