People are being assured that the information they put on Census forms tonight won't be shared with any other government departments.
It follows concerns expressed by some people that the information they supply could be used to alter their entitlements.
In reply to a query from a pensioner who said she didn't want to put her daughter on the form in case it affected her fuel allowance, Kathleen Goulding from Census Publicity says it won't be an issue.
She says all information is converted into anonymous statistics…