The senior Crown Court judge said he found it difficult to believe that it was beyond the ability of departments such as Social Services and Her Majesty's Revenue and Customs (HRMC) to do so.
Judge McFarland said since everyone had a National Insurance number, the two agencies between them should be able to determine when someone was claiming benefits they were not entitled to.
His comments came as he suspended 61-year-old James Jennings' six month sentence for three years after he pleaded guilty to four charges involving benefit frauds amounting to £25,000, claimed over a six-year period up to 2010.
Judge McFarland said it was unfortunate the authorities had taken up to 2011 to uncover the fact that the Co Antrim man, who had been initially legally receiving invalidity benefit, had began working again and had failed to notify changes in his circumstances.
In addition to his suspended sentence, the judge ordered that £5000 raised by his family be paid to the Social Services.
Judge McFarland said even though the authority was making deductions from Jennings' benefits, it would take years, if at all, for the full debt to be repaid.
Defence solicitor advocate Clive Nevin estimated that it would take Jennings, a man in poor health, at least the next ten years to repay the agency.
He said Jennings, from Osterley Park, Newtownabbey, deserved credit for his guilty plea and that the monies he'd claimed were not used to fund high living.