A.R.S. § 42-5045

Notwithstanding any other law, a person who is under nineteen years of age and who is engaging or continuing in business in this state is not required to obtain a transaction privilege tax license or to remit the tax levied by this chapter or chapter 6 of this title or any duly enacted special district transaction privilege tax imposed under title 48 if the gross proceeds of sales or gross income derived from the person's business is not more than $10,000 for the calendar year.