Typical path: Pay → Tax Withholding → Update Federal W-4. Menu names vary by employer, so each step below tells you what to search for if a label differs.
Sign in to MyADP, open Pay, select Tax Withholding, update the federal W-4 section, enter only the steps from your W-4 plan, and submit. The change usually takes effect within 1 to 2 pay periods. Verify it on your next paystub.
Use your employer login at your company ADP portal or the ADP mobile app. Complete any multi-factor step your employer requires.
Select Pay from the main menu. This is also where you view paystubs — keep a recent one open in another tab for reference.
Choose Tax Withholding (sometimes labeled Tax Withholding Elections). You should see your current federal and state elections.
Select Update next to the federal W-4. Review your current elections first so you only change what your plan requires.
Type your Step 4(c) extra-withholding amount (per paycheck) or Step 4(b) deduction figure (yearly). Check Box 2(c) only if your plan calls for it on this job.
Submit the change and save the confirmation. Check your next paystub FIT line — if nothing changed after two pay periods, ask HR whether the update was received.
Run the free check, then unlock your per-paycheck Step 4(c) amount.