A former police officer who kidnapped, raped and murdered Sarah Everard has lodged an appeal to reduce the length of his sentence.
Couzens, 48, had been planning the crime for at least a month.
A Court of Appeal official said on Wednesday: "An application (for permission to mount an appeal against sentence) has been lodged."
When sentencing Couzens, Lord Justice Fulford said the abuse of his "unique position" as a policeman was a "vital factor" in his decision to give him a whole life tariff.
He added that the seriousness of the case was "exceptionally high".
After sentencing, Ms Everard's family said that while nothing could bring her back, knowing Couzens "will be imprisoned forever brings some relief".
Unless the appeal is successful, Couzens will remain part of a relatively small group of killers in the UK who will die behind bars for their crimes.
Earlier this month, Reading terrorist Khairi Saadallah lost a Court of Appeal challenge against his whole-life sentence for the murders of three men, following a hearing at the Royal Courts of Justice.
An independent inquiry will now look into the "systemic failures" by police over Ms Everard's death.
Meanwhile, five officers from four different forces are facing disciplinary action over messages about Wayne Couzens.