Why do you need to use my name / address / date of birth / national insurance number? 

So that your records can be identified by the government department or agency who hold records about you, we need to use information which is unique to you. This is why we use name, in combination with your address, date of birth, and for your economic  and student loans records, your national insurance number so that it is easy to find your records.  This is all transferred securely and the government departments and agencies cannot see your survey answers.