Alabama Income Withholding For Support (AIW FS) is a program used by the state of Alabama to collect court-ordered child support payments. AIW FS requires employers to withhold a portion of an employee's wages to ensure that the court-ordered child support payments are paid on time and in full. AIW FS can also be used to deduct alimony and other maintenance payments from an employee’paychecKIWIIFFSFS consists of two different types of income withholding: voluntary and mandatory. Voluntary income withholding is when an employer voluntarily agrees to deduct a portion of the employee’s wages to pay the court-ordered child support payments. Mandatory income withholding is when an employer is required by law to deduct a portion of an employee’s wages to pay the court-ordered child support payments.