The employee should complete Form A-4 electing their withholding percentage and return it to the employer. Out-of-State Resident Working for an Arizona Business.All wages, salaries, bonuses or other compensation paid for services performed in Arizona are subject to state income tax withholding, with exceptions. All AZ employees are required to complete Form A-4, AZ Withholding Percentage Election. Complete Arizona Form WEC to claim an exemption from Arizona income tax withholding. This guide will help you file formation documents, get tax identification numbers, and set up your company records. Record-Keeping; Reporting changes to your business; Providing information to your employees; Reporting New Hires. Record-Keeping. This form is connected to the Arizona Joint Tax Application (JT-1). To register, please fill out the Form 42A808 - EFW2 PIN and return it us.