[Melody Pond]

This website has the laws for every state.

http://www.everytattoo.com/tattoolaws.shtml

I don't know where you are so I couldn't pick states close to you but I randomly looked at a few and so far I have found Florida.

(3) No body of a minor shall be tattooed without the written notarized consent of the parent or legal guardian.

http://www.everytattoo.com/floridalaw.shtml

Ohio

(A) No person shall perform a tattooing procedure, body piercing procedure, or ear piercing procedure with an ear piercing gun on an individual who is under eighteen years of age unless consent has been given by the individual's parent, guardian, or custodian in accordance with division (B) of this section.

(B) A parent, guardian, or custodian of an individual under age eighteen who desires to give consent to a business to perform on the individual under age eighteen a tattooing procedure, body piercing procedure, or ear piercing procedure performed with an ear piercing gun shall do both of the following:

(1) Appear in person at the business at the time the procedure is performed;

(2) Sign a document provided by the business that explains the manner in which the procedure will be performed and methods for proper care of the affected body area following performance of the procedure.

http://www.everytattoo.com/ohiolaw.shtml

and New Jersey

A person commits a disorderly persons offense if he knowingly tattoos or engages in body piercing of a minor under the age of 18 years without first having obtained the written permission of the minor's parent or legal guardian or, if neither exists, a person who stands in place of a parent.

http://www.everytattoo.com/newjerseylaw.shtml

Just have a look around that website at states by you and see what you can find.