For the purpose of proper administration of this article and to prevent evasion of the tax imposed by this article it is presumed that all gross proceeds of sales and gross income derived by a person from business activity classified under a taxable business classification comprise the tax base for the business until the contrary is established.
A.R.S. § 42-5023
Presumption as to tax base
Official source: Arizona State Legislature. Reproduced from public-domain Arizona statutes; confirm against the official source for the current text. Not legal advice.