Ms Everard’s boyfriend reported her missing the following day.
Her body was found hidden in an area of woodland in Ashford, Kent on March 10.
She was discovered in a large builder’s bag and was formally identified through her dental records.
A post-mortem examination has taken place but no cause of death has yet been given.
Couzens, who worked on the Parliamentary and Diplomatic Protection Command unit, was not on duty at the time of Ms Everard’s disappearance.
The defendant, from Deal in Kent, was charged on Friday and appeared at Westminster Magistrates’ Court the following day.
On Tuesday, Couzens will make his first appearance at the Old Bailey.
He is expected to appear in court by video link from custody before Judge Mark Lucraft QC, the Recorder of London, from 10am.
During the hearing, the judge is expected to set a timetable for the case.
Ms Everard’s death has sparked vigils across the country in her memory and demands for action to tackle violence against women.
Images of women being manhandled by police officers at a vigil on Clapham Common on Saturday night have prompted shock and widespread condemnation.
Ms Everard’s last known movements have been aired previously in court.
She had visited a friend in the Clapham Junction area on March 3 and left at around 9pm to make the two-and-a-half-mile journey home.
She called her boyfriend for around 14 minutes and there was no activity on her mobile phone after that.
Ms Everard was captured alone on CCTV at 9.15pm and again 9.28pm, and was later caught on the camera of a marked police car at 9.32pm.
At around 9.35pm, a bus camera captured two figures on Poynders Road and a white Vauxhall Astra with its hazard lights flashing.
Another bus camera captured the same car with both front doors open.
The registration of the vehicle, later confirmed to be a car hired in Dover, Kent, was caught and tracked by police as it left London towards Kent.