The CJEU has ruled in MB v Secretary of State for Work and Pensions  Case C‑451/16, that the previous position in the United Kingdom under which the acquired gender of a transsexual person was not recognised for the purpose of determining the qualifying age for a state pension if that person was and remained party to a subsisting marriage was incompatible with equal treatment under Council Directive 79/7/EEC.
Council Directive 79/7/EEC of 19 December 1978 on the progressive implementation of the principle of equal treatment for men and women in matters of social security prohibits discrimination on grounds of sex with respect to state benefits, including old age and retirement pensions; however, it allows Member States to exclude from its scope the determination of pensionable age for the purpose of granting old age and retirement pensions. The UK has exercised that right of derogation, as a result of which the pensionable age for a woman born before 6 April 1950 is 60 and that for a man born before 6 December 1953 is 65.
MB was born a male in 1948 and married in 1974. MB began to live as a woman in 1991 and underwent sex reassignment surgery in 1995. MB does not, however, hold a full certificate of recognition of her change of gender because in order for a certificate to be granted her marriage would have had to be annulled and she and her wife wished to remain married “for religious reasons”  which were not specified. When MB reached the age of 60 in 2008 and applied for a state retirement pension, her application was rejected because without a full gender recognition certificate she could not be treated as a woman for the purposes of determining her statutory pensionable age.
MB challenged that decision, arguing that the provision that she must not be married was discrimination prohibited by EU law. The UK Supreme Court referred the matter to the CJEU for an Opinion as to whether such a situation was compatible with the Directive: see MB v Secretary of State for Work and Pensions  UKSC 53. (It should be noted that Schedule 5 to the Marriage (Same Sex Couples) Act 2013, which came into force in December 2014, amended s.4 Gender Recognition Act 2004 so that a Gender Recognition Panel must now issue a full gender recognition certificate to a married applicant if the applicant’s spouse consents: however, the 2013 Act is not applicable to the dispute in the proceedings on which the opinion of the CJEU was sought.)
The Court distinguished the facts in the present case from those in Hämäläinen v Finland  ECHR 787, which concerned the legal recognition of a change of gender in relation to civil status. By contrast, the issue in the present case was “the comparability of the situations of the persons concerned in the light of legislation the subject matter of which is specifically entitlement to a State retirement pension” . The UK legislation at issue in the main proceedings treated a person who changed gender after marrying than a person who had kept his or her birth gender and was married, even though those persons were in comparable situations .
The UK Government argued that the purpose of avoiding the existence of a marriage between persons of the same sex could justify the requirement that a person who changed gender should seek an annulment of an existing marriage, given that national law did not, at the material time allow same sex marriage . However, “the objective invoked by the United Kingdom Government ” did not correspond to any of the derogations allowed by the directive . The Court had already held that the directive did not allow Member States to treat differently persons who have changed gender after marrying and persons who have kept their birth gender and are married, with regard to the age of entitlement to a State retirement pension . The national legislation at issue in the main proceedings therefore constituted direct discrimination on grounds of sex and was prohibited by Directive 79/7.
The Court ruled as follows:
“Council Directive 79/7/EEC of 19 December 1978 on the progressive implementation of the principle of equal treatment for men and women in matters of social security, in particular the first indent of Article 4(1), read in conjunction with the third indent of Article 3(1)(a) and Article 7(1)(a) thereof, must be interpreted as precluding national legislation which requires a person who has changed gender not only to fulfil physical, social and psychological criteria but also to satisfy the condition of not being married to a person of the gender that he or she has acquired as a result of that change, in order to be able to claim a State retirement pension as from the statutory pensionable age applicable to persons of his or her acquired gender” .