W-2 Box 2 — Federal income tax withheld
Total federal income tax your employer withheld from your paychecks during the year, based on your Form W-4 elections.
At a glance — Box 2
- Box name
- Federal income tax withheld
- Reports to
- Form 1040, Line 25a
- Check against
- The sum of the 'Federal Income Tax' line on every pay stub for the year, or your final pay stub's year-to-date federal withholding total.
What Box 2 means
Box 2 reports the total federal income tax withheld from your wages during the year. Your employer calculates it from your Form W-4 — your filing status, whether you checked the multiple-jobs box in Step 2, any dependents or credits entered in Step 3, and any other income, deductions, or extra per-paycheck withholding you entered in Step 4 — applied against the withholding tables in IRS Publication 15-T. Box 2 also picks up any flat-dollar 'extra withholding' amount you asked for on line 4(c) of your W-4.
Box 2 is federal income tax only. It does not include Social Security tax (Box 4) or Medicare tax (Box 6) — those are FICA taxes withheld under a completely separate system — and it does not include state or local income tax (Boxes 17 and 19) or any estimated tax payments you sent directly to the IRS on Form 1040-ES (those show up on Form 1040, Line 26, not here). It can also include the 20% excise tax withheld on an excess golden parachute payment, a narrow rule that applies to some departing executives.
Withholding assumes each job is your only source of income. If you or your spouse work more than one job, each employer withholds as if that paycheck is the household's entire income, which routinely under-withholds two-earner and multiple-job households. Form W-4 Step 2 — using the IRS Tax Withholding Estimator, the Multiple Jobs Worksheet, or the box-checking shortcut for two similarly-paid jobs — and IRS Publication 505 both exist to correct for this.
Bonuses and other supplemental wages are often withheld differently than your regular paycheck. Employers can use a flat 22% rate on supplemental wages instead of running them through your regular W-4 formula, which can under-withhold if your marginal tax bracket is 24% or higher. Once your supplemental wages from one employer exceed $1 million in the calendar year, the excess must be withheld at a mandatory flat 37% rate regardless of what your Form W-4 says. Either way, Box 2 is a payment toward your tax bill, not the bill itself — your actual liability is computed on Form 1040 when you file.
Tax return implications
- Flows to Form 1040, Line 25a, combined with 1099 withholding (Line 25b) and any other withholding (Line 25c).
- Compared against your total tax liability on Form 1040 to determine your refund or balance due.
- Under-withholding can trigger the estimated tax penalty on Form 2210 unless you meet a safe harbor — generally 90% of the current year's tax, or 100% of last year's tax (110% if your prior-year AGI was over $150,000, or $75,000 if married filing separately).
- Multiple employers' Box 2 amounts all sum on Line 25a — verify the total against your own pay records, since employers don't coordinate withholding with each other.
- Doesn't offset Social Security, Medicare, or state/local tax liability — those are reconciled separately from Boxes 4, 6, 17, and 19.
Common pitfalls & things to check
- Multiple jobs (yours or a working spouse's) are the most common cause of a surprise balance due — each employer withholds as if its paycheck is your only income.
- The 22% flat supplemental-wage rate on a bonus can be too low if your marginal bracket is 24%, 32%, 35%, or 37% — it's a withholding shortcut, not a tax calculation.
- The mandatory 37% rate only kicks in once your cumulative supplemental wages from that employer top $1 million for the year — it's not triggered by a single large bonus below that threshold.
- A flat extra-withholding amount you entered on your W-4 keeps withholding every pay period until you submit a new W-4 — a common cause of over-withholding after a one-time need (a big tax bill, a side-gig year) has passed.
FAQ
Is Box 2 the same as my federal tax liability?
No. Box 2 is how much was withheld during the year. Your actual tax liability is computed on Form 1040 and can be higher or lower than Box 2 — the difference is your refund or balance due.
Why is Box 2 zero on my W-2?
Either you certified 'Exempt' on your Form W-4 — a separate certification you sign when you had no federal tax liability last year and expect none this year, not the same as the 'extra withholding' line — or your wages were low enough that the IRS withholding tables produced no withholding for your filing status.
How does Box 2 relate to my Form W-4?
Your employer computes Box 2 by running your W-4 elections through the IRS withholding tables for every paycheck. Changing your W-4 mid-year only affects withholding going forward — it doesn't retroactively change what's already been withheld.
Why was my bonus withheld at a different rate than my regular paycheck?
Bonuses are 'supplemental wages.' Employers commonly withhold them at a flat 22% rate instead of running them through your regular W-4 formula, which can be more or less than your actual marginal rate — it's corrected automatically when you file your return.
Related W-2 boxes
Box 1 — Wages, tips, other compensation
Your taxable federal wages for the year — gross pay minus pre-tax deductions like traditional 401(k), Section 125 cafeteria plan contributions, and pre-tax HSA.
Box 3 — Social security wages
Your wages subject to Social Security tax, capped at the annual wage base. Differs from Box 1 because traditional 401(k) deferrals are not excluded.
Box 4 — Social security tax withheld
The Social Security tax your employer withheld — exactly 6.2% of Box 3 (plus Box 7 tips), capped at 6.2% of the annual wage base.
Box 5 — Medicare wages and tips
Your wages subject to Medicare tax. Unlike Social Security, there is no wage base cap — Box 5 can exceed Box 3 on high salaries.
Reconciling your W-2 at tax time? Use the paycheck calculator to verify expected federal, Social Security, and Medicare withholdings on your salary, and the federal income tax calculator to estimate your refund or balance owing before you file.
Related Calculators
Paycheck Calculator
Federal, state, FICA withholding, net take-home, W-4 alignment
Federal Income Tax Calculator
10–37% brackets, $15,750 standard deduction, progressive calculation
W-4 Withholding Calculator
Form W-4 steps, correct federal withholding, avoid penalties
FICA & Social Security
6.2% SS to $176,100, 1.45% Medicare, 0.9% additional Medicare
Tax Refund Estimator
Estimate federal refund, withholding vs liability, adjustments
401(k) Calculator
Contribution limits, employer match, tax-deferred growth
Sources
W-2 box definitions per IRS General Instructions for Forms W-2 and W-3 and IRC §6051. Rates and thresholds current for tax year 2025 (file by April 15, 2026); 2026 figures included where published.