The Arizona transaction privilege tax (TPT) is actually a tax on a vendor for the privilege of doing business in the state. To elect an Arizona withholding percentage, an employee must complete Arizona Form A-4, and submit it to their employer.If you include tax in your price (i.e. As of the 2023 tax year, Arizona has a flat income tax rate of 2.5 percent. Find out if the goods or services you will be selling are subject to Iowa sales tax. Find out if you need to pay use tax. Find out if the goods or services you will be selling are subject to Iowa sales tax. Find out if you need to pay use tax. Arizona has a flat 2.50 percent individual income tax rate. Arizona has a 4.9 percent corporate income tax rate.