Supplementary Benefit was part of the social security system in the United Kingdom. It replaced National Assistance in 1966. It was means-tested and paid to people on low incomes. It stopped and was replaced by Income Support on 11 April 1988.
To get it a person had to show that their savings were less than £6000 and the weekly money they had to live on was less than they needed. It could be paid on top of other benefits, but not to people who were working.