From today, the cost of changing one’s legal gender comes down from £140 to £5 to make it easier for transgender people to afford.
The reduction, allied to taking the process online, follows a promise to make applying for a gender recognition certificate "kinder and more straightforward", made by Equalities Minister Liz Truss in September.
Announcing the new fee, Ms Truss said: "As we build back better, we want transgender people to be free to live and to prosper in modern Britain.
"In the National LGBT Survey, 34% of transgender people told us that the cost of applying for a certificate was holding them back from doing so.
"Today we have removed that barrier, and I am proud that we have made the process of getting a certificate fairer, simpler and much more affordable."
Under existing rules, legally changing one’s gender involves completing a two-year waiting period and a review by, or appearance before, a specialist panel, as well as the fee.
Many LGBT campaigners believe the current system, enshrined in the Gender Recognition Act, is not fit for purpose and have called for it to be replaced with a simpler statutory declaration and self-identification.
Following a public consultation, Ms Truss announced in September that the government had rejected calls for people to be able to self-identify their gender and change their birth certificates without a medical diagnosis.
Instead, the minister said that the cost of applying for a gender recognition certificate would be reduced to a "nominal amount" and that the process would be moved online.
But the Equality and Human Rights Commission (EHRC) called it a "missed opportunity to simplify the law on gender recognition".
The LGBT Foundation said it was "incredibly disappointed", as the reforms fail to take into account "the views expressed in the consultation responses".
The experiences of trans and non-binary people, it added, "have been pushed to the side" and it said it was also disappointed "to see that the government has decided not to use this opportunity to allow non-binary people the chance to gain legal recognition of their gender".
Further details are due to be announced by the government in due course.
Some US states are trying to make it harder for people to change their gender.
Earlier this month Arkansas became the first US state to outlaw gender-affirming medical treatments or surgery for minors.