A completed pay run can be undone if changes need to be made or corrections are required. Once undone, the pay run can be updated and recalculated before being completed again.
Steps:
Navigate to Payroll > Pay Runs > Completed Pay Runs.
Click the cog wheel next to the relevant pay run.
Select Undo Pay Run.
The pay run will move back to the In Progress section, where you can make the required changes.