The question of legality regarding body art on minors varies from state to state. For instance, in California, it is illegal to tattoo a minor – period. However, body piercing is permitted with either the presence of a parent or guardian, or written permission that has been notarized.
There seems to be much confusion and deception regarding this issue, especially by tattoo shops that can’t afford to turn away the business of tattooing minors. These shops try to apply the body piercing statutes (that allow piercing with parental consent) to rationalize tattooing of minors, which is not okay. If you are in doubt as to what the law is in your state, contact your local health department and ask. It’s always better be informed of the law, especially since judges will always tell you that ‘ignorance of the law is no excuse’.