Back Dated NI Liabilities Reported in Next Pay Run

Currently any back dating of NI reported changes the reports in the month the change should have happened. This has caused us to miss an underpayment of NI and HMRC have fined the client. Our previous software reported back dated NI calculations in the next run and included the underpayment in the P32. The client is also not happy as historical posting and journals are now not accurate and there are no before and after reports to assist with the corrections required.