65-year-old Terrence Hutchings claimed more than £50,000 in state benefits over five years even though he was working as a bingo caller in the Rhondda.
He was reported to the authorities by an anonymous tip off.
Prosecutor Alexander Greenwood said "He was evasive and vague about his situation. In interview Hutchings said that he believed he could work 16 hours a week before having to declare that he was working. But it was a mistaken belief because he should have declared any hours he was working."
Mr Hutchings was given an eight month suspended sentence and ordered to complete 120 hours unpaid work by a judge a Merthyr Tydfil Crown Court.
His defence barrister said he was "utterly crestfallen. He never lived the high life. This is not a champagne swilling individual living on state benefits."