The census is a survey that households in England and Wales have to do every 10 years.
The census traditionally falls in March or April because people are less likely to be on holiday during that time.
This year it has to be completed by 'Census Day' which falls on Sunday 21st March.
So why is it important that we do it?
By answering the questions on the survey it gives local authorities a better understanding of the communities they serve.
This includes information about transport, education and healthcare.
What if I forget?
Field officers will be visiting households which haven't submitted a census by late March to ask them to complete the form on the doorstep.
The census must be completed by law. If it isn't completed, or false information is supplied, you could be fined up to £1,000.
However some questions are labelled as being voluntary so it is not an offence if they're not answered.
Who should fill it in?
The person who owns or rents (jointly owns or rents) the property, or is responsible for paying the household bills or expenses should fill in the census.
Can I answer separately from the rest of the household?
You can contact the Office for National Statistics and request an individual access code which will allow you to answer separately and anonymously from the rest of your household.
But someone must still complete a census for your household.
What's different this year?
For the first time those aged 16 and over will be asked about their sexual orientation and gender identity.
The household section will include a questions about your use of renewable energy.
How do I start a census form?
This year will be the first time where the majority of forms will be filled in online.
Households can fill in an online version of the census from a smartphone, tablet or computer - or alternatively the can request a paper copy.
You will need the access code from a letter that has been sent from the Office for National Statistics.
This code is for everyone in the household and should be kept safe and only shared with the people you trust.