The survey contractor, the Office for National Statistics (ONS), have access to respondents’ contact details to allow it to carry out the survey.
Mae gan gontractwr yr arolwg, y Swyddfa Ystadegau Gwladol, gopi o'r data personol er mwyn caniatáu iddynt gynnal yr arolwg a pharatoi'r set ddata terfynol.