If you decide to be employed in the beauty, massage or nail technology industry your employer will take care of this for you. All you need to do is provide them with the appropriate accredited certification.
If however, you decide that you would want to work as a mobile therapist, from your home or even open your own salon you will need insurance. This will aid you in any claim made against you from treatments gone wrong, allergic reactions, people having an accident at your premises and in some cases legal slander disputes.
You cannot get insurance without the correct certification in each and every treatment you perform. If you do treat with out insurance all liability will be on yourself and your assets if things go wrong. Please ensure you are adequately insured.
Beauty massage and nail therapy insurance available here.