Just be aware that all the information that you give is available to the following authorities any time they want it.
It's also compulsory with fines for not complying.a) is required or permitted by any enactment,
b) is required by a Community obligation,
c) is necessary for the purpose of enabling or assisting the Board to exercise any of its functions,
d) has already lawfully been made available to the public,
e) is made in pursuance of an order of a court,
f) is made for the purposes of a criminal investigation or criminal proceedings (whether or not in the United Kingdom),
g) is made, in the interests of national security, to an Intelligence Service,
h) is made with the consent of the person to whom it relates, or
i) is made to an approved researcher."
https://www.theregister.com/2011/03/25/confidentiality_of_census_data_not_guaranteed/
