You ran the numbers — now file them. Pick your payroll system below for the exact screens to open, what to type, and how to confirm it worked. Menu names vary by employer setup, so each guide tells you what to look for if a label differs.
Enter them in your employer's payroll portal — the system where you view paystubs. Open the tax section (often called Tax Elections or Tax Withholding), type only the steps from your plan — such as a Step 4(c) dollar amount — and submit. Changes usually take effect within 1 to 2 pay periods and are not retroactive.
Pay → Tax Elections → Federal W-4 → Edit
Use the Pay worklet to open Tax Elections and edit your federal W-4.
Pay → Tax Withholding → Update Federal W-4
Update federal withholding from the Pay section of MyADP.
Settings → Pay Details → Federal Taxes
Edit federal tax settings from your Pay Details page.
Pay → Tax Withholding → Federal W-4
Update federal withholding in the self-service portal.
After submitting, check your next paystub's federal tax (FIT) line. If it did not change after two pay periods, ask HR whether the update was received — some employers batch changes by payroll cycle.
Run the free 30-second check to get your withholding direction, then unlock the exact per-paycheck figure.
Run the free check