PAYE98010 | Accounting: end of year: record / reverse revenue loss
From HM Revenue & Customs · PAYE Manual
When HMRC choose not to pursue an underpayment (debt), or in cases where the underpayment cannot be collected, if permitted you can record the underpayment as a Revenue Loss (remission / write off). You will be able to record or reverse a Revenue Loss from the Underpayment Details screen which is accessed using the Financial Events Summary screen. The PAYE Service will only allow the full amount of the Revenue Loss to be reversed.