Always keep an employee active until their last pay period has been exported. An inactive or deleted employee cannot be exported to payroll.
If you’re using a Hand Punch, Finger Scanner, Web Punch, or PIN system, you don’t need to revoke the badge, since it is the employee’s employee code. Something you would never give to another employee.
It’s best to deactivate employees, rather than deleting. This way you can still run reports and view data about this employee. However if several years have gone by and you don’t need to see that data anymore, you can delete them.