The 2021 census has begun as local authorities try to determine how many people are living in here and neds of the the population.

And tomorrow (March 21) is the day when we are all required, by law, to fill in our census forms.

The census is a survey of people and households in England and Wales, and it takes place every 10 years.

It is an official count of every person and household in the country, and gives the government the most accurate estimate of who lives where and what they do.

The aim is to build "a detailed snapshot of our society", which helps ministers and local authorities plan and fund local services such as education, doctors' surgeries and roads.

Run by the Office for National Statistics (ONS), the census asks questions about you, your household and your home.

The aim is to provide information for future planning

For people living in England, Wales and Northern Ireland, this year's census day is Sunday 21 March.

Census questions ask about every person living at the property, including their age, race, occupation and relationship status.

For the 2021 census, preparation began several years ago before a white paper was brought to parliament in 2018, followed by a rehearsal the year after.

Background work included user and topic research, testing and evaluation and trying out ideas on people at census events.

Possibly - but you'll be given chances to avoid the penalty.

By law, you must complete or be accounted for in the census and anyone who doesn't fill in the census will be contacted by a census officer.

They'll encourage you to complete it and even help people access any support needed to fill in the form.

If you still don't return or submit a completed census, you will be committing a crime and you will be contacted by the non-compliance team.

If prosecuted, you may have to pay a fine of up to £1,000 plus court costs.

Providing false information can also lead to a fine.

The field officers will be wearing PPE and won't need to enter your house.

You do not have to answer the questions marked as voluntary.

People staying in the UK for under three months do not have to fill out a census, but everyone else should be covered by one - including students and those who have gone abroad for under a year.

Every household has been sent a code to use online to complete the census.

A paper form is delivered to all households, but people are being encouraged to complete the form online this year.

For the first time, there will be voluntary questions on gender identity and on sexual orientation for over-16s.

In the UK, there are no official figures for those who identify their gender as different from the sex registered at birth.

Gathering this information will help develop policy, provide services and improve equality, the ONS says.

We'll have to wait until March next year to read the initial findings from this year's census, while the final release is another 12 months later in March 2023.