Why Does My Federal Withholding Vary Each Paycheck?

Department of the Treasury

An employee is responsible for how much taxes are withheld from his check because the withholding largely depends on the information he supplies his employer. Depending on certain circumstances, his federal withholding may change with each paycheck.

Form W-4

Your federal taxes withheld from each paycheck should be based on your most recent W-4 information.

Factors

Your allowances, filing status, income and the IRS withholding tables are also used to calculate your federal tax withholding.

Allowances

Generally, the more allowances you claim on your W-4, the less federal taxes are withheld from your paycheck. Each time you change your W-4 to reflect more allowances, your paycheck reflects less taxes.

Commission

If you are paid commission plus a salary, and the commission gets processed as normal pay, it will place you in a higher tax bracket, changing your federal withholding.

Hourly Employees

If you are an hourly employee and your hours for each pay period are different, the amount of tax withheld varies, because your taxes withheld also depend on your income.

References

• Epinions: Federal Tax Withholding -- Keep it Under Control!