Households should have started to receive their Census letters in the post.
The once-in-a-decade survey has taken place since 1801 and gives the most accurate estimate of all people and households in England and Wales.
Letters containing a code to fill in the Census online will be posted between March 3 and March 13. Residents can then use their computer, tablet or phone to fill in the survey.
The census will include questions about your sex, age, work, health, education, household size and ethnicity. And, for the first time, there will be a question asking people whether they have served in the armed forces, as well as voluntary questions for those aged 16 and over on sexual orientation and gender identity
Census results will be available within 12 months, although personal records will be locked away for 100 years and kept safe for future generations.