Question: A recently divorced employee refiled her Form W-4 to claim fewer withholding allowances. She included her name and address, but only the last four digits of her Social Security number (SSN).requested that she complete another form with her full SSN, but she balked, saying that wasn’t necessary, since the W-4 is an internal form only. Is this a valid form?
Answer: No. The form contains detailed instructions on how employees are to complete it, and truncating SSNs isn’t mentioned. Moreover, the W-4 isn’t strictly an internal form. You must send a copy to the IRS upon its request. If the employee still refuses to provide you with a valid form, withhold on the basis of an old form that you know is valid. If you don’t have an old form, withhold using single/zero status until she provides you with a valid form.