(a) If a taxpayer has failed to file a return or if the Tax Collector is not satisfied with the return or payment of tax required, the Tax Collector may redetermine the tax due, plus penalties and interest, and notify the taxpayer, as provided and prescribed by A.R.S. Sections 42-1108 and 42-1109.

(b) Estimates by the Tax Collector. Any estimate made by the Tax Collector is to be made on a reasonable basis. The existence of another reasonable basis of estimation does not, in any way, invalidate the Tax Collector’s estimate. It is the responsibility of the taxpayer to prove that the Tax Collector’s estimate is not reasonable and correct, by providing sufficient documentation of the type and form required by this Chapter or satisfactory to the Tax Collector.