Most of those politicians had already left the chamber, after either failing to be re-elected or moving into the upper house, leaving a trail of unpaid bills behind them.
Between just 34, who left the chamber in 2013, some €20,000 was racked up.
But the glaring gap in the bar's takings only came to light last summer, when a contractor, Compass Group, was brought in to manage the Palazzo Montecitorio hangout.
The company noted that takings were down 30 percent over the previous years, Corriere reported.
Whether or not the politicians were just forgetful or in a hurry, the bar managers have decided enough is enough, and so have created a so-called “receipt control team” who will track deputies who haven't paid.
Staff have also been told to only serve those who come with a receipt in hand. The company has taken a hard line, telling staff: "No receipt, no consumption."
“Discreet, but inflexible, their job is to observe and, when necessary, intervene to ask the MPs to pay their bill,” Corriere wrote.
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The wood-panelled bar is modestly priced, although the chamber's MPs did grumble in 2012 when prices rose, pushing the cost of a coffee up to €0.80 and the price of a sandwich to €2.50.
Italian MPs are also among the highest paid in Europe, taking home an average of €172,000 a year, according to figures from 2013.