Refer to Arizona Withholding Tax Ruling (WTR) 16-4 to determine if a worker is an employee or an independent contractor for Arizona withholding tax purposes. To elect an Arizona withholding percentage, an employee must complete Arizona Form A-4, and submit it to their employer.Who is require to withhold? • Withholding Agent. In the city of Phoenix, TSMC Arizona will represent the world's most advanced semiconductor technology in the United States. If you have any doubt about the requirement to withhold, go ahead and do it and use a Form 1042. If you have any doubt about the requirement to withhold, go ahead and do it and use a Form 1042. Those who opt out or are not permitted to be included in the PTE election must file their own Arizona income tax returns to claim the PTE tax credit. Did the organization have any excess business holdings in the tax year? Part IV Supporting Organizations.