A Surrey council has taken back over £35,000 during an amnesty where people could admit they did not qualify for a single person's council tax discount.
Spelthorne council said 89 taxpayers contacted the authority during the seven-week amnesty because their circumstances had changed.
The discount offers a 25% reduction on council tax to people living alone.
The council said it not only recovered funds but had also cut the number of cases it needed to investigate.
It said some 30% of Spelthorne households were benefiting from the concession, but recent research had suggested that up to 5% of those claims were potentially fraudulent.
Councillor Vivienne Leighton, cabinet spokesman for finance and resources, said: "I am very pleased that a number of residents have come forward - they will have their bills recalculated without penalty.
"It's fair to expect everyone to pay their proper share and anyone now found falsely claiming a single person discount will face action which may include prosecution or a financial penalty."
The amnesty started on 5 June and expired on 23 July.