Federal Income Tax Withholding (FITW) is calculated from each employee's Form W-4, taxable wages for the pay period, and current IRS withholding rules. Amounts can change from paycheck to paycheck even when the W-4 has not changed.
What Determines FITW
- Form W-4 elections (filing status, dependents, extra withholding, and related steps)
- Taxable wages for the period (gross pay minus applicable pretax deductions)
- Current IRS withholding tables and guidance
Employees who want different federal withholding must submit an updated W-4.
Why FITW Can Vary
- Pretax deductions (such as 401(k) or HSA) lower taxable wages and can reduce FITW
- Bonuses, commissions, or one-off payments change taxable wages for that run
- W-4 updates (dependents, additional income, extra withholding) change the calculated amount
When an Employee Questions FITW
- Review the W-4 on file for that employee.
- Estimate expected withholding with a third-party tool such as the IRS Tax Withholding Estimator or PaycheckCity Calculator, using taxable wages (gross minus pretax deductions).
- Compare the estimate to the processed FITW.
- If the amounts align with the W-4, explain that withholding follows the form on file and that an updated W-4 is required to change it.
- If the amounts differ significantly from the estimate, email help@bernieportal.com for a review.
Employer Responsibilities
Employers withhold federal tax according to each employee's W-4. Employers are not responsible for the outcome of an employee's personal tax return and should not advise employees on how to complete the W-4. Point employees to a third-party estimator or a tax professional when they need help choosing elections.
Disclaimer: BerniePortal provides payroll processing services and general information related to payroll administration. This article is for general reference only and does not constitute legal, tax, or financial advice.