For tax purposes, copies of all Forms W-4 should be retained for a minimum of seven years. We must obtain a new Form W-4 from these employees by February 15 th each year. If a new W-4 is not received each year, then we must withhold payroll taxes on these employee as if they were single with no exemptions. If a new employee refuses to provide a Form W-4, then we must withhold payroll taxes on the employee as if the employee were single with no exemptions. If we receive an invalid Form W-4, then we must withhold payroll taxes on the employee as if the employee were single with no exemptions.
Special rules apply to nonresident alien employees.