What form is the employee's withholding allowance certificate?

The employee's withholding allowance certificate is represented by the W-4 form. This form is crucial for employees to specify the amount of federal income tax to be withheld from their paychecks. When an employee fills out a W-4, they provide information such as their filing status and number of dependents, which helps employers calculate the correct amount of tax to withhold based on personal circumstances.

In contrast, the W-2 form is issued by employers to report wages and tax withholdings for employees at the end of the tax year, while the W-9 form is used to provide taxpayer identification information for independent contractors. The 1099 form is utilized to report various types of income received by non-employees, including freelancers. Therefore, the W-4 is specifically dedicated to allowing employees to indicate their withholding preferences, thereby making it the correct answer in this context.