The Central Statistics Office has reminded anyone who has not received a Census form to contact its office ahead of the Census taking place on Sunday.
Two million forms have been distributed to date, though around 20,000 remain to be delivered.
Speaking on RTÉ's Morning Ireland, CSO Senior Statistician Deirdre Cullen reminded people that the Census is totally anonymous, and participation is legally required.
Ms Cullen said that some people living in apartment complexes may not have forms.
She urged those without forms to contact the CSO on 1850-201-604 to arrange delivery.
Ms Cullen said that five people were prosecuted after the last Census for not completing the form.
If you haven't got a #Census2016 form, how to get one:
— Cathal Mac Coille (@CathalMacCoille) April 21, 2016
Freetext FORM to 50400
Go to help desk at https://t.co/C821xwlGpb
Lo-Call 1850 201604
