The 2011 Northern Ireland Census is to be launched later on Monday.
Organised by the Northern Ireland Statistics and Research Agency (NISRA), the census will take place on 27 March.
Everyone living in Northern Ireland is required by law to take part.
Registrar General Norman Caven said that on Sunday 27 March everyone will be asked to complete a census questionnaire to provide an accurate picture of Northern Ireland's population.
"Knowing how many people live in Northern Ireland allows us to work out the types of services they will need in the future," he said.
The information gathered by the census will be used by government to help plan important services such as houses, schools, and roads," he said.
A questionnaire will be delivered to every house in the middle of March and can be completed online or posted back.
Dr Caven said the questionnaire would be easy to complete.
"Most of the questions can be answered by simply ticking a box. It takes about 10 minutes to complete per person, but the results will inform policy and determine resources for the next decade," he said.
"For anyone having difficulties, help will be available through a dedicated website and a telephone helpline.
"Census staff will also provide assistance if required."