The fastest way to withhold more taxes from your paycheck is to give your employer a new Form W-4 with a flat dollar amount written on Line 4(c), “Extra withholding.”1Internal Revenue Service. Form W-4 – Employee’s Withholding Certificate Your employer will subtract that amount from every paycheck on top of the federal tax already being calculated from your filing status and wages. You can file a new W-4 whenever you want, as many times a year as you want.
Reasons to Take More Out
The clearest signal is a balance due at tax time, but you do not need to wait for that. The IRS recommends reviewing withholding after any major life change: marriage, divorce, a new child, a new job, or a job loss.2Internal Revenue Service. Managing Your Taxes After a Life Event Each of these can move your bracket, change your filing status, or change the credits you qualify for.
Income that arrives without withholding is the other common trigger. Freelance work, rental income, interest, and dividends all produce tax liability that your paycheck is not covering. Raising your W-4 withholding is one way to catch up before the shortfall grows into a penalty.
The Lines on Form W-4 That Actually Increase Withholding
Only Steps 1 and 5 (personal information and signature) are required for every employee. Steps 2 through 4 are optional, and they are where withholding gets adjusted up or down.3Internal Revenue Service. FAQs on the 2020 Form W-4 To take more out, focus on these:
Line 4(c): Extra Withholding
Enter a specific dollar amount, not a percentage. Your employer adds that number to every paycheck’s federal tax withholding.1Internal Revenue Service. Form W-4 – Employee’s Withholding Certificate On a biweekly schedule, $50 on Line 4(c) becomes $1,300 in additional federal withholding over 26 pay periods. This is the single most direct control on the form.
Line 4(a): Other Income
If you expect non-job income during the year that will not have tax withheld from it — interest, dividends, retirement distributions — enter the total here. Do not include self-employment income.1Internal Revenue Service. Form W-4 – Employee’s Withholding Certificate The payroll system treats that figure as additional taxable wages and pulls more tax accordingly, spread across your remaining paychecks. If you would rather not disclose the source to your employer, skip 4(a) and put an equivalent lump sum on 4(c) instead.
Step 2: Multiple Jobs or a Working Spouse
Complete Step 2 if you hold more than one job or if you are married filing jointly and your spouse also works. You have three choices:1Internal Revenue Service. Form W-4 – Employee’s Withholding Certificate
- Use the IRS Tax Withholding Estimator online (most accurate, and the right choice if there is self-employment income in the picture).
- Fill out the Multiple Jobs Worksheet on page 3 of the W-4 and put the result on Line 4(c).
- If there are only two jobs total and they pay roughly the same, check the box in Step 2(c) on the W-4 for each job. When the pay gap is wide, this option overwithholds on the smaller job and underwithholds on the larger one.
When you complete Steps 3 and 4 in a multiple-job situation, do so only on the W-4 for the highest-paying job. Leave those steps blank on every other W-4.
Step 3: Be Careful With Dependent Credits
Step 3 lowers your withholding by baking in credits like the Child Tax Credit, which is worth up to $2,200 per qualifying child for 2026.4Internal Revenue Service. Child Tax Credit If you want more tax withheld, you can enter a smaller amount here or leave it blank. You still claim the full credit on your tax return.
Step 4(b): Leave It Blank
Line 4(b) is for anticipated deductions above the standard deduction. Entering a number here decreases withholding. If your goal is to withhold more, leave 4(b) blank so the payroll system assumes only the standard deduction.1Internal Revenue Service. Form W-4 – Employee’s Withholding Certificate
Picking the Right Number for Line 4(c)
The IRS Tax Withholding Estimator is a free tool that projects your total tax for the year, compares it to what you have already had withheld, and tells you what to enter on your W-4.5Internal Revenue Service. Tax Withholding Estimator Before you start, pull together your most recent pay stubs for every job in the household, your most recent tax return, and any records for other income you expect.6Internal Revenue Service. IRS Tax Withholding Estimator Helps Taxpayers Get Their Federal Withholding Right
You can set a target outcome inside the estimator — breaking even, or aiming for a specific refund — and it will adjust the recommended per-paycheck amount. Running it mid-year concentrates the fix over fewer remaining pay periods, so the number on Line 4(c) will be larger than it would be in January. At the end, the estimator can generate a pre-filled W-4 you print and hand to payroll.5Internal Revenue Service. Tax Withholding Estimator
Submitting the Form and Confirming It Worked
Send the completed W-4 to your employer through the payroll portal or hand it to human resources. Employers must put the new form into effect no later than the start of the first payroll period ending on or after the 30th day after they receive it.7Internal Revenue Service. Topic No. 753, Form W-4, Employees Withholding Certificate Most payroll systems process the change in one or two pay cycles.
Look at your next pay stub. Federal income tax withheld should go up by the amount you entered on Line 4(c) (plus any effect from other steps you changed), and your net pay should drop by roughly that same amount. If the numbers do not move the way you expected, contact payroll before the next cycle so a mistake does not compound for months.
Side Income: W-4 Adjustment or Quarterly Estimated Payments
For freelance, rental, or investment income, you have two ways to pay the tax during the year. The first is the W-4 route already described — Line 4(a) for the income figure, or an equivalent flat amount on Line 4(c). The W-4 instructions note that using 4(a) this way generally removes the need to make separate estimated payments on that income.1Internal Revenue Service. Form W-4 – Employee’s Withholding Certificate
The second route is quarterly estimated tax payments using Form 1040-ES.8Internal Revenue Service. About Form 1040-ES, Estimated Tax for Individuals The 2026 due dates are April 15, June 16, September 15, and January 15, 2027; a deadline falling on a weekend or holiday moves to the next business day.9Internal Revenue Service. Individuals 2 – Estimated Tax FAQs You can also mix the two: extra withholding on your W-4 plus smaller estimated payments to close the gap.
Bonuses Are Withheld Separately
Bonuses, commissions, and other supplemental wages are typically withheld at a flat 22 percent, no matter what your W-4 says. Supplemental wages over $1 million in a calendar year are withheld at 37 percent on the excess.10Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide If you sit in the 24 percent bracket or higher, that 22 percent flat rate leaves a gap. Line 4(c) on your regular W-4 is where you close it.
W-4 Does Not Control State Tax
Form W-4 covers federal income tax only. Most states with an income tax use their own withholding certificate and do not follow the federal form. Check with your employer or your state’s tax agency if you also need to raise state withholding; adjusting the federal side alone can still leave a state balance due.
How Much Withholding Is Enough to Avoid a Penalty
The IRS charges an underpayment penalty when your total withholding and estimated payments for the year fall short of a safe harbor. You are safe if you paid in at least the smaller of 90 percent of your current-year tax or 100 percent of your prior-year tax. If your prior-year adjusted gross income was over $150,000 (or $75,000 if married filing separately), the 100 percent figure rises to 110 percent.11Office of the Law Revision Counsel. 26 US Code 6654 – Failure by Individual to Pay Estimated Income Tax
No penalty applies if you end up owing less than $1,000 after subtracting withholding and refundable credits.11Office of the Law Revision Counsel. 26 US Code 6654 – Failure by Individual to Pay Estimated Income Tax The penalty itself functions as interest on the shortfall, set at the IRS underpayment rate — 6 percent per year as of Q2 2026, compounded daily.12Internal Revenue Service. Internal Revenue Bulletin 2026-08 The rate changes quarterly, tied to the federal short-term rate plus three percentage points.13Internal Revenue Service. Quarterly Interest Rates Withholding counts as paid evenly across the year regardless of when it happens, which is why an increase to Line 4(c) late in the year can still fix an early-year shortfall.