Today marks Scotland's so-called Census Day.
All Scots adults are required to fill in the crucial document, which provides officials with a snapshot of the country when making vital decisions.
Letters inviting Scots to participate in this year’s census have been in circulation since the end of last month.
Submissions can be posted either online or through a physical document.
Here’s everything you need to know about Census Day.
What is Census Day?
The Census Day, March 20, is the date referred to inside the census document.
All of the information provided in the form must reflect their circumstances from as of that date.
What does the census ask?
The census asks a number of questions about your household and the people that reside there.
Topics include the number of people who live in your property, household relationships, age, sex, health and employment status.
Questions about your household will ask about the type of accommodation you live, if you rent or own your home and details about the number of cars owned in the household.
Individual questions will ask about the job you work, your health and education.
Why is the census important?
The census has been crucial document for Scots to fill in every ten years since it was introduced in 1801.
Answers provided help the Scottish Government build a picture of the population when making a series of important policy decisions.
And it has also benefited local communities in the past.
An example of this came in 2011 when researchers at Dundee City Council used census data to identify which parts of the city had the highest concentration of people with little or no English.
This resulted in the council help improve access and attendance for council-led language classes for non-English speaking residents.
Census data has also used by NHS Western Isles to ensure that rural communities remain connected to essential health services.
Do I need to fill it in?
The census is deemed to be a legal responsibility by the Scottish Government and every household must complete it.
Failure to complete the census could result in a huge £1,000 fine of even prosecution.
How can I complete the census?
Letters inviting Scots to complete the census have been in circulation since February 28 this year.
The letter provides people with an Internet Access Code, which should be entered into the census website - this will then bring up an online version of the document.
You can also submit the census on paper by ordering a paper questionnaire here.
