To obtain a withholding tax account number, employers must complete the Application available online at MyAlabamaTaxes.alabama.gov. This job aid explains how to update your tax withholding elections in Workday.When preparing your tax withholding forms, consult a tax professional. Incomplete W-4 Forms will be returned to an employee which, in turn, might hold up your paycheck. Employers use this form to determine the amount of tax to be withheld from an employee's paycheck. Before making any entries, see the Note below, and if applicable, complete the worksheet in the instructions. Submit this form to request that additional taxes be withheld from your pay. MCEA Moving Pay Verification Form. Leave. As an employer, you must complete the Residency Certification Form for each employee. Before making any entries, see the Note below, and if applicable, complete the worksheet in the instructions.