Registering a freelancer

As a sole trader, if a freelancer is doing occasional work under me, do they have to be registered as an employee?

Hi Elsea Brown
The hirer will be required to complete the CEST tool to determine whether the work carried out is deemed to be employment or self employment. 
If they are providing their services through their own LTD company then the same tool is used to determine whether IR35 rules apply. 
You can find the CEST tool at: 
Check employment status for tax
Thank you