The Central Statistics Office is reminding people that they are legally obliged to fill out their Census document - or they could face prosecution.
This Sunday is census night and the CSO says the Census will only be used for compiling statistical tables.
Forms are still being delivered to homes around the country and anyone who hasn't received their form is being asked to contact them.
Deirdre Cullen is from the CSO.
"Where you are on the night of Sunday 24, you go on that Census form. But if your spouse is away on the night you put them down as an absent person so then you still have the family unit.
"Foreign vistors to Ireland on Census night will be on the Irish Census. People in hospitals, nursing homes, people on cruise ships, the Irish Census is everybody who is in Ireland on the night of Sunday 24."