The document necessary to report an employee's withholding allowances is called what?

The document required to report an employee's withholding allowances is the W-4 form. This form is filled out by the employee and submitted to their employer, indicating how much federal income tax should be withheld from their paycheck based on their personal situation, including factors like marital status and the number of dependents or allowances claimed. By using the W-4 form, employees can help ensure that the correct amount of tax is deducted from their wages, which can help avoid large tax bills or penalties at the end of the year.

The W-2 form is used by employers to report the total annual wages paid to employees and the amount of taxes withheld, but it does not pertain to withholding allowances directly. Form 1040 is the individual income tax return form that taxpayers use to report their income to the IRS and calculate their tax liability, while Form I-9 is utilized to verify an employee's eligibility to work in the United States. Each of these forms serves different purposes in the payroll and tax reporting processes, making the W-4 form the correct answer for reporting withholding allowances.