I have a client who took on a new employee with a start date in February 2020, but their first PAYE payroll date was the March payroll run. The Government guidelines state that "You can only claim for furloughed employees that were on your PAYE payroll on or before 28 February 2020". At what date would this employee be deemed to be "on your PAYE payroll" - Feb 2020 ( qualifying for furloughing) or Mar 2020 ( not qulaifying). My guess is the devil is in the detail, bu there doe snot appear to be any further guidance that I can find.
Keep safe and well
Hope this Job Retention Scheme article will help you