Getting married changes how much federal tax should come out of each paycheck, and the fix is a new Form W-4 submitted to your employer. If both spouses work, you also need to tell payroll about the second income using one of three IRS-approved methods. Here is how to update your W-4 after marriage so your withholding matches what you will actually owe.
The IRS treats you as married for the entire tax year if you are married on December 31, so even a late-year wedding changes that year’s return.1IRS. Publication 4491 – Filing Status The sooner both spouses submit updated W-4s, the smaller the gap between what gets withheld and what you owe.
Why Two Paychecks Under-Withhold After Marriage
When you check “Married filing jointly” on your W-4, your employer’s payroll system assumes your paycheck is the household’s only income. It applies the full $32,200 joint standard deduction and starts calculating taxes from the lowest bracket.2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 If your spouse’s employer does the same thing, both systems independently credit the full deduction and the lower brackets. The deduction gets counted twice, and more of your combined income sits in artificially low brackets all year.
Each paycheck has less tax withheld than it should, and the shortfall compounds with every pay period. By April, the couple owes the difference in one lump sum. Step 2 of the W-4 exists to prevent exactly this. Complete it correctly and payroll withholds as if it knows about the other job.
Change Your Name with Social Security First
If either spouse is taking a new last name, update it with the Social Security Administration before submitting a new W-4. The name on your W-4 must match your Social Security records. A mismatch between your W-2 and your Social Security card can delay your refund.3Internal Revenue Service. Name Changes and Social Security Number Matching Issues Until the SSA processes your name change, use your former name on both your W-4 and your tax return.
To update your name, you need your marriage certificate (an original or certified copy, not a photocopy), a photo ID such as a driver’s license or passport, and proof of citizenship such as a birth certificate or U.S. passport.4Social Security Administration. U.S. Citizen – Adult Name Change on Social Security Card Start at ssa.gov/number-card/replace-card to see if you can complete the process online. Otherwise, schedule an appointment at a Social Security office by calling 1-800-772-1213. Once you have the updated card, submit a W-4 with your new name.
Pick Your Filing Status
Most married couples file jointly. Married Filing Jointly gives you the largest standard deduction, the widest tax brackets, and access to credits that shrink or disappear under Married Filing Separately.
Married Filing Separately exists mainly for couples who need legal separation of tax liability, such as situations involving a spouse’s unpaid debts, certain student loan repayment strategies, or pending legal disputes. The trade-offs are steep. If one spouse itemizes, the other must also itemize, even if the standard deduction would have been better.5Internal Revenue Service. Other Deduction Questions Many credits, including education credits and the earned income credit, become unavailable or heavily restricted. Unless you have a specific reason to file separately, joint filing is almost always the better choice.
If You Both Work, Choose One of Three Methods
This is the single most important part of the update. Pick one method and use it. Combining methods will over-withhold.
The IRS Tax Withholding Estimator
The free calculator at irs.gov/W4App walks you through both spouses’ income, expected deductions, and credits. It produces a specific dollar amount to enter on your W-4 and can generate a pre-filled form.6Internal Revenue Service. Tax Withholding Estimator Have recent pay stubs from both jobs before you start. This method is the most accurate because it uses your actual numbers, and it works well when you are updating mid-year.
The Multiple Jobs Worksheet
Page 3 of the W-4 instructions includes a worksheet that calculates the extra withholding you need based on both jobs’ combined income.7Internal Revenue Service. Form W-4 2026 Employees Withholding Certificate Complete the worksheet once and enter the result on the W-4 for the higher-paying job. The lower-earning spouse should also submit a fresh W-4 if theirs is out of date.
The Step 2(c) Checkbox
If both spouses earn roughly similar wages, each can check the box in Step 2(c) on their own W-4. The IRS says this option works best when the lower-paying job pays more than half of what the higher-paying job pays.7Internal Revenue Service. Form W-4 2026 Employees Withholding Certificate The box tells the payroll system to withhold at the higher single rate, which roughly corrects for the double-counting problem. When the income gap between spouses is wide, this shortcut becomes less accurate. Use one of the other two methods instead.
Filling Out the 2026 W-4
The form is one page with four steps plus a signature.
Step 1: Personal Information
Enter your name (matching your Social Security card), address, Social Security number, and filing status. Most newlyweds check “Married filing jointly.” Checking “Married filing separately” instructs payroll to withhold at the less favorable rates that apply to that status.7Internal Revenue Service. Form W-4 2026 Employees Withholding Certificate
Step 2: Multiple Jobs or Spouse Works
If both spouses work, this is where you implement the method you chose above. For the Step 2(c) checkbox method, both spouses check the box on their own W-4. For the Estimator or the Multiple Jobs Worksheet, leave the checkbox blank; those results go on line 4(c). Use one option only.
If only one spouse works, skip Step 2. The default married-filing-jointly calculation already handles single-income households correctly.
Step 3: Dependents
Multiply each qualifying child under 17 by $2,200 and each other dependent by $500, then enter the total.8Internal Revenue Service. Child Tax Credit Enter the dependent amount on only one spouse’s W-4, typically the higher earner, so the credit is not counted twice.
Step 4: Other Adjustments
Three optional lines fine-tune your withholding:
- Line 4(a), other income: enter estimated annual amounts for income without withholding, such as interest, dividends, rental income, or freelance work. This increases withholding to cover the extra liability.
- Line 4(b), deductions: if your itemized deductions will exceed the $32,200 joint standard deduction, enter the difference. For 2026, the state and local tax deduction cap rose to $40,400, up from $10,000, so couples with large mortgage interest and high state taxes are more likely to benefit from itemizing. An amount on this line decreases withholding.7Internal Revenue Service. Form W-4 2026 Employees Withholding Certificate
- Line 4(c), extra withholding: enter the dollar amount from the IRS Estimator or the Multiple Jobs Worksheet. Add any additional per-paycheck amount if you want a larger refund or need to cover other tax obligations.
State Withholding and Benefits Enrollment
The federal W-4 is only half the picture. Most states with an income tax also require a withholding form, and some use their own form rather than accepting the federal W-4. Ask your employer’s payroll department whether you need a separate state form reflecting your new filing status. Rules and form names vary, and some states still use an allowance-based system.
Marriage is a qualifying life event for employer-sponsored benefits, including health insurance, dental coverage, and flexible spending accounts. Most employers give you a 30- to 60-day window after your wedding to add a spouse, switch plans, or adjust contributions. Miss the window and you typically wait until the next open enrollment. Adding a spouse to your health plan through pre-tax salary deductions changes your taxable wages, which circles back to withholding, so handle benefits enrollment and the W-4 update together.
Avoiding an Underpayment Penalty
When withholding falls short, the IRS charges interest on the shortfall, currently 7% per year, compounded daily.9Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026 You can avoid the penalty entirely if your balance due is under $1,000, or if your withholding covers at least 90% of your current-year tax or 100% of last year’s tax, whichever is less.10Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty For couples whose prior-year adjusted gross income exceeded $150,000, the 100% threshold rises to 110%.
The year you marry is the riskiest for underpayment because filing status, income, and withholding are all changing at once. If you married late in the year and cannot adjust enough through the remaining paychecks, make an estimated tax payment directly to the IRS before December 31 to close the gap. The IRS Tax Withholding Estimator is the fastest way to check whether you are on track.
Verify After You Submit
Hand your completed W-4 to your employer’s payroll or HR department, or enter it through your company’s online payroll portal. Your employer must put the new withholding into effect no later than the start of the first payroll period ending on or after the 30th day after receiving your form.11Internal Revenue Service. Topic No. 753, Form W-4, Employees Withholding Certificate
Once processed, check the federal income tax line on your next pay stub. If both spouses updated their W-4s, compare both stubs so the combined withholding looks reasonable against your projected tax. Your combined federal withholding for the year should roughly equal 10 to 22% of your combined taxable income, depending on your bracket. If the numbers look wildly off, contact payroll before another month passes.
Run the IRS Tax Withholding Estimator again around September or October, using year-to-date wages from both pay stubs.6Internal Revenue Service. Tax Withholding Estimator A late-year checkup catches drift from bonuses, raises, or income changes the original W-4 could not anticipate, and adjusting your Step 4(c) extra withholding in the fall leaves enough paychecks to correct course before year-end.