The amount of federal income taxes withheld should approximate the tax liability the employee will owe to the federal government.

The purpose of federal income tax withholding is to collect taxes throughout the year, so that the taxpayer's liability is paid gradually rather than in one lump sum at the end of the year. The goal is for the amount withheld to be as close as possible to the actual tax liability, so there are no surprises at tax time. However, various factors can affect the accuracy of the withholding, such as changes in income or deductions, so it is possible that an employee may owe additional taxes or receive a refund after filing their tax return.