The DWP has widened the scope of its project to check whether more claimants who were moved from incapacity benefit to ESA were given the wrong award and are due back payments.
Originally, the DWP were planning to check the awards of 570,000 claimants who were moved from incapacity benefit to ESA between 2011 and 2014.
However, they have now decided to also check 30,000 claimants who were moved to ESA from 2015 onwards. It had been thought that new guidance issued to decision makers in 2015 meant that the problem had been solved from that date.
However, further checks by the DWP have revealed that errors continued to be made even after the guidance was issued.
So far, 207,000 cases have been checked out of a total of 600,000.
Of these, 149,000 got no backdated award and 58,000 have received a payment.
The average arrears payment is £6,000 and a total of £328 million has been paid out so far.
You can read more on the .gov website.