IRS Form W-4 is a United States Internal Revenue Service tax form used by employers to determine the correct amount of withholding tax to deduct from an employees' wages. Employees typically fill out a Form W-4 at the beginning of their employment with a new employer. The employees calculates how many deductions they are allowed based on their expected tax filing situation. For every deduction the employee takes, the amount of money that will be withheld from their wages is reduced. It is recommended that taxpayers use the IRS’s Withholding Calculator to calculate their withholding allowances more exactly.

You can download IRS Form W-4 for 2007 here.