A raise, promotion, or second W-2 job changes your annual tax, but employers withhold from each paycheck using the Form W-4 on file. If you never update Step 2 (multiple jobs) or extra withholding after income jumps, you can owe in April even though every stub “looked fine.” This guide is about proactive withholding after income changes. Fixing a past wrong W-4 uses the same form mechanics (How to correct a W-4 withholding mistake).
Paystub literacy: Paycheck deductions basics, How to read your pay stub.
When to submit a new W-4
| Trigger | Why withholding drifts | First move |
|---|---|---|
| Raise / promotion mid-year | Higher bracket exposure; same old W-4 | Run IRS Tax Withholding Estimator with new salary |
| Second job starts | Each employer may withhold as if it were your only job | Complete Step 2 on the W-4s (checkbox, estimator, or worksheet) |
| Spouse starts / stops work | Household income changed | Rebuild estimator with combined wages |
| Big bonus / RSU vest expected | Supplemental withholding may not match full-year tax | Consider Step 4(c) extra flat amount on the main job |
| Side 1099 income grows | W-2 withholding can cover some of it, or use estimates | See Quarterly estimated taxes |
Steps after a raise (single job)
- Open the current Form W-4 from IRS.gov.
- Keep filing status accurate in Step 1.
- Re-enter dependents in Step 3 only on one form if you have multiple jobs.
- Run the IRS Tax Withholding Estimator with the new salary and year-to-date withholding from your latest stub.
- Enter any recommended extra amount in Step 4(c); submit to payroll; confirm the next stub’s federal income tax line moved.
Steps when a second job starts
- List Job A and Job B wages (annualized).
- Pick one Step 2 method: two-jobs checkbox (when the lower-paid job is more than half of the higher-paid job, per Form W-4), IRS Tax Withholding Estimator, or Multiple Jobs Worksheet. Do not stack checkbox + worksheet + estimator extras.
- If you use the checkbox, check it on both jobs’ W-4s.
- Put Step 3 credits and Step 4(a)/(b) items on the higher-paying job only.
- Recheck after 2–3 pay cycles; sketch April with Estimate your refund before filing.
Worked example
Sam earns $62,000 at Job A. In July, Job B starts at $24,000. Old W-4s ignored Step 2. Job B is less than half of Job A ($24k < $31k), so the Form W-4 similar-pay checkbox path is a weaker fit than the estimator. Sam runs the IRS Tax Withholding Estimator once for the mid-year start, follows only its resulting W-4 instructions (extra withholding on Job A via Step 4(c) as recommended; no separate Step 2 checkbox stacked on top), and leaves credits blank on Job B. Sam rechecks stubs after two cycles and re-runs the estimator if pay changes rather than relying on a napkin underwithholding projection.
Checklist
- Update the W-4 within 1–2 pay periods of a raise or new job.
- Use one multiple-jobs method only.
- Confirm stubs after the change.
- Separate true W-4 mistakes from “I need estimates for 1099 income.”
- Revisit after bonuses or a spouse job change.
Educational only. Not tax advice. Form W-4 instructions and the IRS estimator are the controlling references; payroll cutover timing varies by employer.