A flurry of deaths of transgender prisoners underlines the need for action to address the issue, a watchdog has said.
Prisons and Probation Ombudsman Nigel Newcomen called for jails to be more flexible and proactive in managing such inmates.
He said his office has historically received few complaints from prisoners identifying themselves as transgender and has investigated relatively few deaths in custody.
However, the numbers have been climbing more recently, Mr Newcomen said. "These events made the need to address this issue all the more pressing," he added.
He published a bulletin on lessons that could be learned from investigations into five deaths and 33 complaints between 2008 and August 2016.
There have been other cases since. An investigation has been launched after Jenny Swift, an inmate at HMP Doncaster, an all-male prison, was found dead in her cell on December 30.
About 80 transgender individuals are believed to be in jails in England and Wales.
Prisons house male and female prisoners separately and will usually determine gender based on that which is recognised by law.
Under prison instructions in place during the period covered by the report, inmates would ordinarily be housed according to their legally recognised gender.
They were allowed to request a switch if they were "sufficiently advanced in the gender reassignment process".
According to the guidance, prisons should consider moving a prisoner to the estate of the gender with which they identify.
The report said: "Our investigations have found that this did not always happen in a proactive, timely, or consistent way."
In a number of cases concerning claims of discrimination, bullying and harassment, the watchdog found that, while steps were taken to protect the prisoner, officials did not properly investigate the allegations raised.
Several complaints have also been received from transgender female prisoners about restrictions to gender expression that were based on security considerations, with most concerning clothing or make-up.
In one case cited in the report a prisoner complained that she had not been permitted to wear make-up for her security photo.
Regulations that guide the care and management of transgender prisoners in England and Wales are covered in a new Prison Service Instruction (PSI) issued in November.
Mr Newcomen said the PSI "reflects the appropriately heightened awareness of transgender issues in prison - and in society as a whole".