The next official Census may ask people to reveal their income, their nationality and whether they have a second home.
The Office for National Statistics (ONS) will trial a number of new questions in a test run next year.
For the first time, it will ask respondents to state whether they are English, Welsh, Scottish, Northern Irish, Irish or another nationality. Previous Censuses have asked about ethnicity but not nationality.
The test on May 13 will collect information about people's incomes and, crucially, about the sources of their money.
A question about income was considered for the last Census in 2001 but eventually rejected.
People will be asked the month and year of their entry into the UK in a bid to collect extra information about international migration.
The questionnaire will set out to identify the number of people who have a regular second address and look at how often they live there and why - such as whether it is a holiday home or a weekend residence.
Another new question will collect information on proficiency in English, Welsh, British Sign Language and other languages.
In Wales, people will be asked how frequently they use the Welsh language.
The test Census will also expand on 2001's question about marriage to include civil partnerships.
