W-4 Changes: How to Fill It Out to Get the Right Withholding
The W-4 form was completely redesigned in 2020 — and most people still fill it out wrong. Here's how to do it correctly to get the right amount withheld from each paycheck.
The W-4 (Employee's Withholding Certificate) tells your employer how much federal income tax to deduct from each paycheck. Get it right and you'll owe a small amount or get a modest refund at tax time. Get it wrong and you'll either owe the IRS a surprise bill — possibly with penalties — or get a large refund that amounts to an interest-free loan you gave the government.
The IRS redesigned the W-4 form in 2020, eliminating the old allowance system entirely. The new form is more precise but also more confusing. Here's what each step actually means.
The W-4 Step by Step
Personal Information
Your name, address, SSN, and filing status. Filing status is the most impactful choice: Single/MFS withholds more (safer against underpayment). MFJ withholds less (appropriate if your combined income fits the married brackets).
Watch out: Married filers who both work should NOT select 'Married filing jointly' on Step 1 without completing Step 2. Doing so will under-withhold.
Multiple Jobs / Spouse Works
Required if you have more than one job or your spouse works. Three options: (a) use the IRS Tax Withholding Estimator, (b) use the Multiple Jobs worksheet on page 3 of the W-4, or (c) check the box (less precise but simple).
Watch out: This step is the most commonly skipped — and skipping it is the most common cause of underpayment penalties for dual-income households.
Claim Dependents
Reduces withholding by your estimated tax credits. For one qualifying child under 17: enter $2,000. For other dependents: $500 each. Only complete this step on ONE W-4 if you have multiple jobs.
Watch out: If your income exceeds $400K (MFJ) or $200K (other), child tax credit phases out. Don't overclaim credits.
Other Adjustments (Optional)
(a) Other income: add non-wage income (freelance, dividends) so it gets withheld. (b) Deductions: if itemizing, enter estimated deductions above the standard deduction to reduce withholding. (c) Extra withholding: flat extra amount per paycheck.
Watch out: Step 4(a) is useful if you have a side business. Step 4(c) is the simplest way to ensure you don't owe at tax time.
Sign and Date
Required. Unsigned W-4 forms are invalid and your employer must withhold at the default single rate.
Common W-4 Mistakes
Mistake 1: Married couple, both working, both select "Married filing jointly" without completing Step 2.
Both employers withhold at the low married rate, ignoring each other. Your combined income pushes you into higher brackets at filing time. Fix: complete Step 2 on one W-4.
Mistake 2: Forgetting about non-wage income.
If you have freelance income, investment dividends, or rental income, no one is withholding from those payments. Use Step 4(a) to add these amounts, or make quarterly estimated tax payments.
Mistake 3: Not updating after a life change.
Getting married, having a child, getting a second job, or buying a home all change your optimal withholding. A W-4 filed years ago may no longer reflect your situation.
The Refund vs. Owing Tradeoff
Many people aim for a large tax refund as a forced savings mechanism. This is rational for some people — but financially, a large refund means you over-withheld all year, giving the IRS an interest-free loan. The average US tax refund in recent years has been $3,000+. Invested at even a modest 5% return, that's $150 in lost interest annually.
On the other hand, underpaying by more than $1,000 can trigger an underpayment penalty. The IRS safe harbor rule: you avoid penalties if your withholding covers 100% of last year's tax bill (110% if your prior year income exceeded $150K).
The ideal outcome: withhold roughly what you'll owe, aiming for a refund or balance due of under $500. The IRS Tax Withholding Estimator is the most reliable tool for achieving this.
Frequently Asked Questions
Should I claim 0 or 1 on my W-4?
The new W-4 doesn't use allowances anymore. Leave Steps 3–4 blank for maximum withholding (conservative). Fill in Step 3 credits to reduce withholding if you have dependents.
How do I fill out a W-4 with two jobs?
Complete Step 2 on your higher-paying job's W-4. Leave Steps 2–4 blank on the lower-paying job's form. Or use the IRS Tax Withholding Estimator.
When should I update my W-4?
After any major life change: marriage, divorce, new child, second job, large raise, home purchase, or receiving a tax bill/large refund.
See what your paycheck should look like
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