Three thousand Jersey census forms completed
More than 3,000 completed census forms have already been returned, Jersey Census Office said.
But it said that other questionnaires should be completed and returned as soon as possible.
The answers people provide on the form must relate to today, Sunday 27 March.
Dr Duncan Gibaut, head of Jersey's Statistics Unit, said the census would "make a difference to everyone's lives over the next 10 years".
In 1821, when the first census was carried out, Jersey had a population of 29,000.
By the last census, in 2001, the population had risen to 87,000.
Guernsey is not taking part in the 2011 census - instead it is pressing ahead with a rolling electronic census.