The rules are changing and being enforced more now, I know in my area and across London and further afield you now need the special treatment licence for a home salon,log cabin/garage any type of conversion as it's a business meaning the council need to come in and check the premises/room has all requirements for health and safety, insurances, nvq cert etc. I know my area you need to be nvq qualified in mani/pedi, enhancements and other services.
I'm in process of opening a shop salon so had to look into all this so they told me loads, they did say so far mobile nail techs don't need one (my area) but they are looking into changing the regulations.
It's becoming a lot stricter which in my opinion is good, so hopefully they'll be less nss and non trained techs about.