This article critiques recent UK transgender law reform. The Gender Recognition Act 2004 is to be welcomed in many respects. Formerly one of the European states most resistant to social change in this area, the UK now occupies pole position among progressive states willing to legally recognise the sex claims of transgender people. This is because the UK is, at least ostensibly, the first state to recognise sex claims irrespective of whether applicants have undertaken any surgical procedures or had hormonal (...) treatments. The article highlights the significance of this development through providing an overview of the trajectory of common law reform around the world. The legislation clearly benefits transgender people unable to undertake surgery due to financial reasons and/or medical contra-indications. It also benefits transgender people whose search for harmony does not require surgical intervention. However, the Act also perpetuates a mental illness model for understanding transgender desires; contributes to the break-up of legally recognised marriages; insists on the permanence of gender crossings and assumes that surgery will occur. The Act also contains exceptions to the generality of legal recognition provided by the state. In this respect the article considers concessions to religious and sporting lobbies. Finally, the article highlights how non-disclosure of gender history prior to a marriage assumes a kind of legal significance under the Act which non-disclosure of other facts generally lacks in relation to marriage. In this regard, the article will contend that a biological understanding of sex operates as a subtext within the Act. (shrink)