You can get a Gender Recognition Cert at 16 here ( you just need to get an adult to apply to the courts for you )Once again Sweden leads the way, not sure about lowering the age to 16 and can do it after a chat with your Doctor without Parental consent it seems? 18, sure do your own thing, 16 though?
Sweden passes law lowering age to change legal gender from 18 to 16
Swedes have been able to change their legally recognised gender since 1972 - but this will make it easier.www.bbc.com
Sweden's parliament passes a law to make it easier for young people to legally change their gender
The Swedish parliament has passed a law lowering the age required for people to legally change their gender from 18 to 16.apnews.com
Sweden passes disputed gender reassignment law
Sweden's parliament on Wednesday passed a controversial law lowering the minimum age to legally change gender from 18 to 16 and making it easier to get access to surgical interventions.www.france24.com