Posted: 15/04/2017 at 14:42
Granma - are you talking about the information that's on the Electoral Register? That information is on public record and as such is available to everyone (advertisers/marketing companies etc) unless you choose to opt out of the 'Open Register' .
As I was previously employed in social work I have always chosen to opt out of the 'Open Register'.
More information and how to do it is here https://www.gov.uk/electoral-register/opt-out-of-the-open-register