The party said the wasted money was equivalent to more than a months' worth of food for a family or over six tanks of fuel.
It added that upper estimates suggested the loss could be as high as £580 per household.
Labour based its analysis on research commissioned from the House of Commons Library in March 2022, which showed a central estimate of £11.8 billion lost to fraud and error through five Government business support schemes.
It said this equated to £419.93 per household in the UK.
Angela Rayner, Labour's deputy leader and shadow secretary of state for the future of work, said: "While families are struggling to make their pay cheques last the month, billions of pounds of hard-earned taxpayers' money has been lost in fraud and written off by the Chancellor, showing how little he and his Government respect UK taxpayers.
"Had the Conservatives not been so wasteful with public funds, they would not need to raise taxes on working people during a cost-of-living crisis.
"Labour will treat taxpayers' money with respect and make Britain work for working people.
"We have put forward a sensible, costed, practical plan that would give people real help right now - the Government must now hold an emergency budget to enact these plans and make a material difference to the millions of pensioners and working people feeling the crunch from the crisis."
A Government spokesman defended its response to the Covid outbreak and said action was being taken to tackle fraud.
"Our £400 billion Covid support schemes were implemented at unprecedented speed and successfully protected millions of jobs and businesses at the height of the pandemic," the spokesman said.
"Fraud is totally unacceptable, and we're taking action on multiple fronts to crackdown on anyone who sought to exploit our schemes and we'll bring them to justice.
"The new Public Sector Fraud Authority will scrutinise our counter-fraud performance, operate a watchlist of individuals and companies linked to organised crime and seize their money."