Reposted by kylie b
Reminder that "biological sex" is not a thing that exists. It is a legal fiction in every place that refers to it.
In the UK, in the equality act, it means "the sex that was written on your original birth certificate." Incidentally, it doesn't matter if that's due to a clerical error.
theguardian.com
‘We were horrified’: parents heartbroken as baby girl registered as male
Parents told Nottinghamshire registrar’s error on birth certificate cannot be changed