In Britain you can legally change your personal details and live as a member of the opposite sex to that recorded at birth.
However, it is not at present possible if you are a UK citizen who has undergone gender reassignment to alter your Birth Certificate. It is possible to obtain other official documents in your new identity such as a passport, driving licence and National Insurance Number.
UK law defines a person's sex by reference to biological criteria at birth and does not recognise that it can be changed by reassignment surgery (Corbett v. Corbett 1971). As a consequence of these rules a female-to-male transsexual for example would not be permitted to marry a woman.
Over the years there have been numerous unsuccessful attempts to change the law. Most recently in Sheffield v United Kingdom 1998 the European Court of Human rights by the smallest of margins again ruled that the UK government's refusal to correct the birth certificates of two transexual women did not violate the European Convention on Human Rights.
In June 2002, the government announced that there would be a review of the law in this area so in the not too distant future it may become possible for the transgendered to change their birth certificate. So watch this space.
The Sex Discrimination (Gender Reassignment) Regulations 1999 extended the Sex Discrimination Act to include a ban on discrimination at work on the grounds of gender reassignment. Employers who breach the Sex Discrimination Act 1975 in respect of discrimination on gender reassignment grounds will be liable in the same manner they would, for example, for discrimination against a woman on the grounds of sex.