Leavers are not removed from the system when the payroll year end is run they are converted to Historical leavers. Any 'L' or 'D' type leavers in the current tax year will become 'H' type leavers once the year end process is run.
All 'H' type leavers will remain on the system until there are no transactions left on the Employees view screen, which are stored in ?_WHIST. The number of periods these transactions remain depends on the settings within Payroll- utilities - set options - page 3 - keep pay period summary
When there are no WHIST records left the employee is marked as Personnel only. When a leaver is marked Personnel only, the personnel re-organisation function determines when the WNAME record is deleted based upon the years to keep records option within personnel.