Thousands of Personal Independence Payments (PIP) claimants are due back payments from as early as April 2016 after a change in benefit rules. The review comes after a Supreme Court handed down a judgement in 2019 that changed the eligibility requirements for the disability benefit. Thousands of reviews are yet to be conducted for PIP claimants who could be owed an average of £5,000 each, the latest figures from the DWP show. The department says it will review 632,286 over the course of the corrections exercise, and had already paid £142million to 219,080 people by March. More than 320,000 peo…