ACT Corrective Services was preparing to cater for about 445 detainees and staff at Christmas lunch celebrations at the Alexander Maconochie Centre on Sunday.

About 410 inmates spent Christmas Day behind bars in the ACT last year, up from 330 detainees on December 25 in 2014.

This year's lunch menu would start with traditional hot turkey and ham with vegetables, followed by Christmas pudding and custard for dessert.

There would be a lighter option of assorted meat and salad rolls with fresh fruit, tea and coffee for dinner.

Detainees have been allowed to decorate their cells within the safety and security requirements of the prison in the lead up to Christmas.

They could also attend numerous services run by the prison's chaplaincy program, including ecumenical services in every area of the Symonston jail, and services for Jewish, Muslim and indigenous inmates.

Each prisoner was offered a Christmas pack from The Salvation Army or Eternity Church this week.

Volunteers from Shine for Kids, an organisation which supports children with a parent in the criminal justice system, will be at visits on Christmas Day to coordinate themed arts and crafts for youngsters.

A spokeswoman for Corrections Minister Shane Rattenbury said Christmas could be a difficult time for those in prison, as well as their family and friends on the outside.

"Family and friends can visit on Christmas Day and ACTION will be running a special service to the AMC from the City bus station on December 25."

Last Christmas, the prison's booming population was split between the main jail and a temporary overflow facility at Symonston as construction continued on expanded accommodation.

A new unit at the AMC, which opened in February, added 112 beds in 56 cells in a bid to ease pressure on the chronically overcrowded prison.

There has been an 11 per cent increase, or 45 prisoners, to the ACT's adult prison population in the year to June 2016, recent figures from the Australian Bureau of Statistics revealed.