Technically I believe the answer is no, they don't need to, but I still recommend it. I've run into problems where terminated employees have gotten wiped out during year-end processing and we've had to manually rekey their information into the eFiling grid. In cases where there were a lot of terminated employees, it was much easier to process out of the history company. When doing that, you have to remember to change to the history company to get to the eFiling history if necessary though. Plus, it's payroll so an extra backup can't hurt.