'Currently there is no single definition of sex or gender identity within the official statistics community. We also recognise that respondents and users may have differing interpretations of these terms. Given this, it is vital that producers clearly define and explain any terminology that they are using. It is the responsibility of statistics producers, rather than OSR, to decide on and explain the definitions used within any data collections and statistical outputs.
This guidance does not set out harmonised standards for sex or gender identity definitions, as this is not within our remit as a regulator. We have, however, looked at how sex and gender identity have been defined within guidance published by other organisations. To provide a framework for using this guidance we have set out our interpretation of these terms. We recognise that there will be differences in how familiar people are with the terms, that some people may prefer to use alternative terms than those set out below and that some people may feel that certain terms do not apply to them.
When we use the term ‘sex’ in this guidance, we are referring to a binary variable categorised as female or male. In the UK, an individual’s legal sex is recorded at birth based on their biological characteristics. Individuals over the age of 18 can apply for a Gender Recognition Certificate (GRC) which enables them to change their legally recognised sex, including on their birth certificate. Where an individual has a GRC, their legally recognised sex may differ from their sex recorded at birth.
When we use the term ‘gender’ in this guidance, we are referring to the socially constructed characteristics and behaviours of men, women, boys and girls. The concept of gender is not fixed and can vary from society to society and can change over time. We acknowledge that there are different interpretations of ‘gender’ and that the history of this term is complex. In addition, within official statistics data collections, the term ‘gender’ has often been used interchangeably with ‘sex’.'
When we use the term ‘gender identity’ in this guidance, we are referring to an individual’s innate sense of their gender. Gender identity is not constrained to the binary male and female categories and includes others such as non-binary and gender fluid. For some individuals their gender identity may be different from their sex recorded at birth, and/or from their legally recognised sex.'