In the UK and most other countries, you need a licence for any treatment that breaks skin. In the UK it's called a 'Special Treatments Licence' and is administered on a local level by the environmental health dept of your local authority/council. The procedure differs slightly from borough to borough, some inspect premises, some don't but they basically want to ensure that you are operating professionally and responsibly in an appropriate environment that will not spread infection. There is no judgement on the skill of the therapist, just on safe practices.
There is a useful self assessment checklist published by the Health Protection Agency in 2011 to help prepare for inspection by licencing authorities.