If you are an employer with employees working in the state of Alabama, you will need to register with the Department of Revenue for a withholding tax account number. If you are an Alabama employer with Alabama residents working outside the state of Alabama, you will need to withhold Alabama income tax on those residents unless you are withholding tax for the state in which the employee is working in. To obtain a withholding tax account number, employers must complete the Application available online at MyAlabamaTaxes.alabama.gov. (MAT) Please go to “I Want To” then “Obtain a new Tax Account”. NOTE: New account numbers assigned will consist of 10 alphanumeric characters beginning with an “R.” Please make sure that the payroll software provider or program that you will be using is aware of the correct account number.